diff --git a/qutebrowser/api/cmdutils.py b/qutebrowser/api/cmdutils.py
index 3939dbb0a..35b089a9f 100644
--- a/qutebrowser/api/cmdutils.py
+++ b/qutebrowser/api/cmdutils.py
@@ -102,7 +102,7 @@ class _CmdHandlerType(Protocol):
     Below, we cast the decorated function to _CmdHandlerType to make mypy aware of this.
     """
 
-    qute_args: Optional[dict[str, 'command.ArgInfo']]
+    qute_args: dict[str, 'command.ArgInfo'] | None
 
     def __call__(self, *args: Any, **kwargs: Any) -> Any:
         ...
diff --git a/qutebrowser/app.py b/qutebrowser/app.py
index 66bd485fc..02304bb34 100644
--- a/qutebrowser/app.py
+++ b/qutebrowser/app.py
@@ -234,7 +234,7 @@ def process_pos_args(args, via_ipc=False, cwd=None, target_arg=None):
     if command_target in {'window', 'private-window'}:
         command_target = 'tab-silent'
 
-    window: Optional[mainwindow.MainWindow] = None
+    window: mainwindow.MainWindow | None = None
 
     if via_ipc and (not args or args == ['']):
         window = mainwindow.get_window(via_ipc=via_ipc, target=new_window_target)
@@ -296,7 +296,7 @@ def open_url(url, target=None, no_raise=False, via_ipc=True):
     return window
 
 
-def _open_startpage(window: Optional[mainwindow.MainWindow] = None) -> None:
+def _open_startpage(window: mainwindow.MainWindow | None = None) -> None:
     """Open startpage.
 
     The startpage is never opened if the given windows are not empty.
diff --git a/qutebrowser/browser/browsertab.py b/qutebrowser/browser/browsertab.py
index 597b8d37c..54cc32c4e 100644
--- a/qutebrowser/browser/browsertab.py
+++ b/qutebrowser/browser/browsertab.py
@@ -125,13 +125,13 @@ class TabData:
     viewing_source: bool = False
     inspector: Optional['AbstractWebInspector'] = None
     open_target: usertypes.ClickTarget = usertypes.ClickTarget.normal
-    override_target: Optional[usertypes.ClickTarget] = None
+    override_target: usertypes.ClickTarget | None = None
     pinned: bool = False
     fullscreen: bool = False
     netrc_used: bool = False
     input_mode: usertypes.KeyMode = usertypes.KeyMode.normal
-    last_navigation: Optional[usertypes.NavigationRequest] = None
-    splitter: Optional[miscwidgets.InspectorSplitter] = None
+    last_navigation: usertypes.NavigationRequest | None = None
+    splitter: miscwidgets.InspectorSplitter | None = None
 
     def should_show_icon(self) -> bool:
         return (config.val.tabs.favicons.show == 'always' or
@@ -225,7 +225,7 @@ class AbstractPrinting(QObject):
         super().__init__(parent)
         self._widget = cast(_WidgetType, None)
         self._tab = tab
-        self._dialog: Optional[QPrintDialog] = None
+        self._dialog: QPrintDialog | None = None
         self.printing_finished.connect(self._on_printing_finished)
         self.pdf_printing_finished.connect(self._on_pdf_printing_finished)
 
@@ -373,7 +373,7 @@ class AbstractSearch(QObject):
         super().__init__(parent)
         self._tab = tab
         self._widget = cast(_WidgetType, None)
-        self.text: Optional[str] = None
+        self.text: str | None = None
         self.search_displayed = False
         self.match = SearchMatch()
 
@@ -878,7 +878,7 @@ class AbstractTabPrivate:
         self._tab = tab
         self._mode_manager = mode_manager
 
-    def event_target(self) -> Optional[QWidget]:
+    def event_target(self) -> QWidget | None:
         """Return the widget events should be sent to."""
         raise NotImplementedError
 
@@ -913,7 +913,7 @@ class AbstractTabPrivate:
     def clear_ssl_errors(self) -> None:
         raise NotImplementedError
 
-    def networkaccessmanager(self) -> Optional[QNetworkAccessManager]:
+    def networkaccessmanager(self) -> QNetworkAccessManager | None:
         """Get the QNetworkAccessManager for this tab.
 
         This is only implemented for QtWebKit.
@@ -943,7 +943,7 @@ class AbstractTabPrivate:
         self._tab.data.inspector = None
         self.toggle_inspector(inspector.Position.window)
 
-    def toggle_inspector(self, position: Optional[inspector.Position]) -> None:
+    def toggle_inspector(self, position: inspector.Position | None) -> None:
         """Show/hide (and if needed, create) the web inspector for this tab."""
         tabdata = self._tab.data
         if tabdata.inspector is None:
@@ -1056,7 +1056,7 @@ class AbstractTab(QWidget):
         self._load_status = usertypes.LoadStatus.none
         self._tab_event_filter = eventfilter.TabEventFilter(
             self, parent=self)
-        self.backend: Optional[usertypes.Backend] = None
+        self.backend: usertypes.Backend | None = None
 
         # If true, this tab has been requested to be removed (or is removed).
         self.pending_removal = False
@@ -1270,7 +1270,7 @@ class AbstractTab(QWidget):
             self,
             code: str,
             callback: Callable[[Any], None] = None, *,
-            world: Union[usertypes.JsWorld, int] = None
+            world: usertypes.JsWorld | int = None
     ) -> None:
         """Run javascript async.
 
@@ -1298,7 +1298,7 @@ class AbstractTab(QWidget):
         self.data.pinned = pinned
         self.pinned_changed.emit(pinned)
 
-    def renderer_process_pid(self) -> Optional[int]:
+    def renderer_process_pid(self) -> int | None:
         """Get the PID of the underlying renderer process.
 
         Returns None if the PID can't be determined or if getting the PID isn't
@@ -1306,7 +1306,7 @@ class AbstractTab(QWidget):
         """
         raise NotImplementedError
 
-    def grab_pixmap(self, rect: QRect = None) -> Optional[QPixmap]:
+    def grab_pixmap(self, rect: QRect = None) -> QPixmap | None:
         """Grab a QPixmap of the displayed page.
 
         Returns None if we got a null pixmap from Qt.
diff --git a/qutebrowser/browser/commands.py b/qutebrowser/browser/commands.py
index ebce4b37a..4258335dc 100644
--- a/qutebrowser/browser/commands.py
+++ b/qutebrowser/browser/commands.py
@@ -105,7 +105,7 @@ class CommandDispatcher:
         background: bool = False,
         window: bool = False,
         related: bool = False,
-        private: Optional[bool] = None,
+        private: bool | None = None,
     ) -> None:
         """Helper function to open a page.
 
@@ -511,10 +511,10 @@ class CommandDispatcher:
         tab: bool,
         bg: bool,
         window: bool,
-        count: Optional[int],
+        count: int | None,
         forward: bool,
         quiet: bool,
-        index: Optional[int],
+        index: int | None,
     ) -> None:
         """Helper function for :back/:forward."""
         history = self._current_widget().history
@@ -975,7 +975,7 @@ class CommandDispatcher:
     @cmdutils.argument('index', choices=['last', 'stack-next', 'stack-prev'],
                        completion=miscmodels.tab_focus)
     @cmdutils.argument('count', value=cmdutils.Value.count)
-    def tab_focus(self, index: Union[str, int] = None,
+    def tab_focus(self, index: str | int = None,
                   count: int = None, no_last: bool = False) -> None:
         """Select the tab given as argument/[count].
 
@@ -1022,7 +1022,7 @@ class CommandDispatcher:
     @cmdutils.register(instance="command-dispatcher", scope="window")
     @cmdutils.argument("index", choices=["+", "-", "start", "end"])
     @cmdutils.argument("count", value=cmdutils.Value.count)
-    def tab_move(self, index: Union[str, int] = None, count: int = None) -> None:
+    def tab_move(self, index: str | int = None, count: int = None) -> None:
         """Move the current tab according to the argument and [count].
 
         If neither is given, move it to the first position.
@@ -1702,7 +1702,7 @@ class CommandDispatcher:
                url: bool = False,
                quiet: bool = False,
                *,
-               world: Union[usertypes.JsWorld, int] = None) -> None:
+               world: usertypes.JsWorld | int = None) -> None:
         """Evaluate a JavaScript string.
 
         Args:
diff --git a/qutebrowser/browser/downloads.py b/qutebrowser/browser/downloads.py
index bdbd910db..78fd997b0 100644
--- a/qutebrowser/browser/downloads.py
+++ b/qutebrowser/browser/downloads.py
@@ -35,7 +35,7 @@ class ModelRole(enum.IntEnum):
 
 
 # Remember the last used directory
-last_used_directory: Optional[str] = None
+last_used_directory: str | None = None
 
 # All REFRESH_INTERVAL milliseconds, speeds will be recalculated and downloads
 # redrawn.
@@ -221,7 +221,7 @@ def suggested_fn_from_title(url_path, title=None):
     ext_whitelist = [".html", ".htm", ".php", ""]
     _, ext = os.path.splitext(url_path)
 
-    suggested_fn: Optional[str] = None
+    suggested_fn: str | None = None
     if ext.lower() in ext_whitelist and title:
         suggested_fn = utils.sanitize_filename(title, shorten=True)
         if not suggested_fn.lower().endswith((".html", ".htm")):
@@ -451,14 +451,10 @@ class AbstractDownloadItem(QObject):
         self.basename = '???'
         self.successful = False
 
-        self.fileobj: Union[
-            UnsupportedAttribute, IO[bytes], None
-        ] = UnsupportedAttribute()
-        self.raw_headers: Union[
-            UnsupportedAttribute, dict[bytes, bytes]
-        ] = UnsupportedAttribute()
+        self.fileobj: UnsupportedAttribute | IO[bytes] | None = UnsupportedAttribute()
+        self.raw_headers: UnsupportedAttribute | dict[bytes, bytes] = UnsupportedAttribute()
 
-        self._filename: Optional[str] = None
+        self._filename: str | None = None
         self._dead = False
 
     def __repr__(self):
diff --git a/qutebrowser/browser/downloadview.py b/qutebrowser/browser/downloadview.py
index 5f67b344d..49d00c446 100644
--- a/qutebrowser/browser/downloadview.py
+++ b/qutebrowser/browser/downloadview.py
@@ -17,10 +17,7 @@ from qutebrowser.utils import qtutils, utils
 
 
 _ActionListType = MutableSequence[
-    Union[
-        tuple[None, None],  # separator
-        tuple[str, Callable[[], None]],
-    ]
+    tuple[None, None] | tuple[str, Callable[[], None]]
 ]
 
 
@@ -67,7 +64,7 @@ class DownloadView(QListView):
 
     def __repr__(self):
         model = qtutils.add_optional(self.model())
-        count: Union[int, str]
+        count: int | str
         if model is None:
             count = 'None'
         else:
diff --git a/qutebrowser/browser/greasemonkey.py b/qutebrowser/browser/greasemonkey.py
index ab63046db..b1c9f38a6 100644
--- a/qutebrowser/browser/greasemonkey.py
+++ b/qutebrowser/browser/greasemonkey.py
@@ -232,7 +232,7 @@ class LoadResults:
         names = '\n'.join(str(script) for script in sorted(self.successful, key=str))
         return f"Loaded Greasemonkey scripts:\n\n{names}"
 
-    def error_str(self) -> Optional[str]:
+    def error_str(self) -> str | None:
         """Get a string with all errors during script loading.
 
         This can be used e.g. for a message.error() call.
diff --git a/qutebrowser/browser/hints.py b/qutebrowser/browser/hints.py
index b3f45610d..49b61c0e7 100644
--- a/qutebrowser/browser/hints.py
+++ b/qutebrowser/browser/hints.py
@@ -187,9 +187,9 @@ class HintContext:
 
     all_labels: list[HintLabel] = dataclasses.field(default_factory=list)
     labels: dict[str, HintLabel] = dataclasses.field(default_factory=dict)
-    to_follow: Optional[str] = None
+    to_follow: str | None = None
     first_run: bool = True
-    filterstr: Optional[str] = None
+    filterstr: str | None = None
 
     def get_args(self, urlstr: str) -> Sequence[str]:
         """Get the arguments, with {hint-url} replaced by the given URL."""
@@ -394,7 +394,7 @@ class HintManager(QObject):
         """Constructor."""
         super().__init__(parent)
         self._win_id = win_id
-        self._context: Optional[HintContext] = None
+        self._context: HintContext | None = None
         self._word_hinter = WordHinter()
 
         self._actions = HintActions(win_id)
@@ -587,7 +587,7 @@ class HintManager(QObject):
                 raise cmdutils.CommandError(
                     "'args' is only allowed with target userscript/spawn.")
 
-    def _filter_matches(self, filterstr: Optional[str], elemstr: str) -> bool:
+    def _filter_matches(self, filterstr: str | None, elemstr: str) -> bool:
         """Return True if `filterstr` matches `elemstr`."""
         # Empty string and None always match
         if not filterstr:
@@ -783,7 +783,7 @@ class HintManager(QObject):
             error_cb=lambda err: message.error(str(err)),
             only_visible=True)
 
-    def _get_hint_mode(self, mode: Optional[str]) -> str:
+    def _get_hint_mode(self, mode: str | None) -> str:
         """Get the hinting mode to use based on a mode argument."""
         if mode is None:
             return config.val.hints.mode
@@ -795,7 +795,7 @@ class HintManager(QObject):
             raise cmdutils.CommandError("Invalid mode: {}".format(e))
         return mode
 
-    def current_mode(self) -> Optional[str]:
+    def current_mode(self) -> str | None:
         """Return the currently active hinting mode (or None otherwise)."""
         if self._context is None:
             return None
@@ -868,7 +868,7 @@ class HintManager(QObject):
                 pass
         self._handle_auto_follow(keystr=keystr)
 
-    def filter_hints(self, filterstr: Optional[str]) -> None:
+    def filter_hints(self, filterstr: str | None) -> None:
         """Filter displayed hints according to a text.
 
         Args:
@@ -1127,7 +1127,7 @@ class WordHinter:
 
     def new_hint_for(self, elem: webelem.AbstractWebElement,
                      existing: Iterable[str],
-                     fallback: Iterable[str]) -> Optional[str]:
+                     fallback: Iterable[str]) -> str | None:
         """Return a hint for elem, not conflicting with the existing."""
         new = self.tag_words_to_hints(self.extract_tag_words(elem))
         new_no_prefixes = self.filter_prefixes(new, existing)
diff --git a/qutebrowser/browser/history.py b/qutebrowser/browser/history.py
index ebcd26e72..298cf72f2 100644
--- a/qutebrowser/browser/history.py
+++ b/qutebrowser/browser/history.py
@@ -86,7 +86,7 @@ class CompletionMetaInfo(sql.SqlTable):
     }
 
     def __init__(self, database: sql.Database,
-                 parent: Optional[QObject] = None) -> None:
+                 parent: QObject | None = None) -> None:
         self._fields = ['key', 'value']
         self._constraints = {'key': 'PRIMARY KEY'}
         super().__init__(database, "CompletionMetaInfo", self._fields,
@@ -134,7 +134,7 @@ class CompletionHistory(sql.SqlTable):
     """History which only has the newest entry for each URL."""
 
     def __init__(self, database: sql.Database,
-                 parent: Optional[QObject] = None) -> None:
+                 parent: QObject | None = None) -> None:
         super().__init__(database, "CompletionHistory", ['url', 'title', 'last_atime'],
                          constraints={'url': 'PRIMARY KEY',
                                       'title': 'NOT NULL',
@@ -159,7 +159,7 @@ class WebHistory(sql.SqlTable):
     url_cleared = pyqtSignal(QUrl)
 
     def __init__(self, database: sql.Database, progress: HistoryProgress,
-                 parent: Optional[QObject] = None) -> None:
+                 parent: QObject | None = None) -> None:
         super().__init__(database, "History", ['url', 'title', 'atime', 'redirect'],
                          constraints={'url': 'NOT NULL',
                                       'title': 'NOT NULL',
@@ -472,7 +472,7 @@ def debug_dump_history(dest):
         raise cmdutils.CommandError(f'Could not write history: {e}')
 
 
-def init(db_path: pathlib.Path, parent: Optional[QObject] = None) -> None:
+def init(db_path: pathlib.Path, parent: QObject | None = None) -> None:
     """Initialize the web history.
 
     Args:
diff --git a/qutebrowser/browser/inspector.py b/qutebrowser/browser/inspector.py
index e60e4a2b8..2b32acf2d 100644
--- a/qutebrowser/browser/inspector.py
+++ b/qutebrowser/browser/inspector.py
@@ -57,7 +57,7 @@ class _EventFilter(QObject):
 
     clicked = pyqtSignal()
 
-    def eventFilter(self, _obj: Optional[QObject], event: Optional[QEvent]) -> bool:
+    def eventFilter(self, _obj: QObject | None, event: QEvent | None) -> bool:
         """Translate mouse presses to a clicked signal."""
         assert event is not None
         if event.type() == QEvent.Type.MouseButtonPress:
@@ -86,7 +86,7 @@ class AbstractWebInspector(QWidget):
         self._widget = cast(_WidgetType, None)
         self._layout = miscwidgets.WrapperLayout(self)
         self._splitter = splitter
-        self._position: Optional[Position] = None
+        self._position: Position | None = None
         self._win_id = win_id
 
         self._event_filter = _EventFilter(parent=self)
@@ -128,7 +128,7 @@ class AbstractWebInspector(QWidget):
             modeman.enter(self._win_id, usertypes.KeyMode.insert,
                           reason='Inspector clicked', only_if_normal=True)
 
-    def set_position(self, position: Optional[Position]) -> None:
+    def set_position(self, position: Position | None) -> None:
         """Set the position of the inspector.
 
         If the position is None, the last known position is used.
@@ -183,7 +183,7 @@ class AbstractWebInspector(QWidget):
             if not ok:
                 log.init.warning("Error while loading geometry.")
 
-    def closeEvent(self, _e: Optional[QCloseEvent]) -> None:
+    def closeEvent(self, _e: QCloseEvent | None) -> None:
         """Save the geometry when closed."""
         data = self._widget.saveGeometry().data()
         geom = base64.b64encode(data).decode('ASCII')
diff --git a/qutebrowser/browser/navigate.py b/qutebrowser/browser/navigate.py
index 956f222b4..97f78f00d 100644
--- a/qutebrowser/browser/navigate.py
+++ b/qutebrowser/browser/navigate.py
@@ -79,7 +79,7 @@ def incdec(url, count, inc_or_dec):
         inc_or_dec: Either 'increment' or 'decrement'.
     """
     urlutils.ensure_valid(url)
-    segments: Optional[set[str]] = (
+    segments: set[str] | None = (
         set(config.val.url.incdec_segments)
     )
 
diff --git a/qutebrowser/browser/network/pac.py b/qutebrowser/browser/network/pac.py
index 20516366e..34116ede0 100644
--- a/qutebrowser/browser/network/pac.py
+++ b/qutebrowser/browser/network/pac.py
@@ -248,7 +248,7 @@ class PACFetcher(QObject):
         with qtlog.disable_qt_msghandler():
             # WORKAROUND for a hang when messages are printed, see our
             # NetworkAccessManager subclass for details.
-            self._manager: Optional[QNetworkAccessManager] = QNetworkAccessManager()
+            self._manager: QNetworkAccessManager | None = QNetworkAccessManager()
         self._manager.setProxy(QNetworkProxy(QNetworkProxy.ProxyType.NoProxy))
         self._pac = None
         self._error_message = None
diff --git a/qutebrowser/browser/qtnetworkdownloads.py b/qutebrowser/browser/qtnetworkdownloads.py
index 3d3c0475a..db3b4a498 100644
--- a/qutebrowser/browser/qtnetworkdownloads.py
+++ b/qutebrowser/browser/qtnetworkdownloads.py
@@ -72,7 +72,7 @@ class DownloadItem(downloads.AbstractDownloadItem):
             reply: The QNetworkReply to download.
         """
         super().__init__(manager=manager, parent=manager)
-        self.fileobj: Optional[IO[bytes]] = None
+        self.fileobj: IO[bytes] | None = None
         self.raw_headers: dict[bytes, bytes] = {}
 
         self._autoclose = True
diff --git a/qutebrowser/browser/qutescheme.py b/qutebrowser/browser/qutescheme.py
index fa7970e6d..f829566f9 100644
--- a/qutebrowser/browser/qutescheme.py
+++ b/qutebrowser/browser/qutescheme.py
@@ -33,7 +33,7 @@ from qutebrowser.qt import sip
 
 
 pyeval_output = ":pyeval was never called"
-csrf_token: Optional[str] = None
+csrf_token: str | None = None
 
 
 _HANDLERS: dict[str, "_HandlerCallable"] = {}
@@ -78,7 +78,7 @@ class Redirect(Exception):
 
 
 # Return value: (mimetype, data) (encoded as utf-8 if a str is returned)
-_HandlerRet = tuple[str, Union[str, bytes]]
+_HandlerRet = tuple[str, str | bytes]
 _HandlerCallable = Callable[[QUrl], _HandlerRet]
 _Handler = TypeVar('_Handler', bound=_HandlerCallable)
 
@@ -93,7 +93,7 @@ class add_handler:  # noqa: N801,N806 pylint: disable=invalid-name
 
     def __init__(self, name: str) -> None:
         self._name = name
-        self._function: Optional[_HandlerCallable] = None
+        self._function: _HandlerCallable | None = None
 
     def __call__(self, function: _Handler) -> _Handler:
         self._function = function
@@ -201,7 +201,7 @@ def qute_tabs(_url: QUrl) -> _HandlerRet:
 def history_data(
         start_time: float,
         offset: int = None
-) -> Sequence[dict[str, Union[str, int]]]:
+) -> Sequence[dict[str, str | int]]:
     """Return history data.
 
     Arguments:
@@ -349,7 +349,7 @@ def qute_gpl(_url: QUrl) -> _HandlerRet:
     return 'text/html', resources.read_file('html/license.html')
 
 
-def _asciidoc_fallback_path(html_path: str) -> Optional[str]:
+def _asciidoc_fallback_path(html_path: str) -> str | None:
     """Fall back to plaintext asciidoc if the HTML is unavailable."""
     path = html_path.replace('.html', '.asciidoc')
     try:
diff --git a/qutebrowser/browser/shared.py b/qutebrowser/browser/shared.py
index ab72690b2..c0c9c540b 100644
--- a/qutebrowser/browser/shared.py
+++ b/qutebrowser/browser/shared.py
@@ -513,7 +513,7 @@ def choose_file(qb_mode: FileSelectionMode) -> list[str]:
 def _execute_fileselect_command(
     command: list[str],
     qb_mode: FileSelectionMode,
-    tmpfilename: Optional[str] = None
+    tmpfilename: str | None = None
 ) -> list[str]:
     """Execute external command to choose file.
 
diff --git a/qutebrowser/browser/webelem.py b/qutebrowser/browser/webelem.py
index 82960cc8d..4eed8be4c 100644
--- a/qutebrowser/browser/webelem.py
+++ b/qutebrowser/browser/webelem.py
@@ -20,12 +20,12 @@ if TYPE_CHECKING:
     from qutebrowser.browser import browsertab
 
 
-JsValueType = Union[int, float, str, None]
+JsValueType = int| float | str |    None
 
 if machinery.IS_QT6:
     KeyboardModifierType = Qt.KeyboardModifier
 else:
-    KeyboardModifierType = Union[Qt.KeyboardModifiers, Qt.KeyboardModifier]
+    KeyboardModifierType = Qt.KeyboardModifiers | Qt.KeyboardModifier
 
 
 class Error(Exception):
@@ -81,7 +81,7 @@ class AbstractWebElement(collections.abc.MutableMapping):  # type: ignore[type-a
 
     def __repr__(self) -> str:
         try:
-            html: Optional[str] = utils.compact_text(self.outer_xml(), 500)
+            html: str | None = utils.compact_text(self.outer_xml(), 500)
         except Error:
             html = None
         return utils.get_repr(self, html=html)
@@ -273,7 +273,7 @@ class AbstractWebElement(collections.abc.MutableMapping):  # type: ignore[type-a
         """Remove target from link."""
         raise NotImplementedError
 
-    def resolve_url(self, baseurl: QUrl) -> Optional[QUrl]:
+    def resolve_url(self, baseurl: QUrl) -> QUrl | None:
         """Resolve the URL in the element's src/href attribute.
 
         Args:
diff --git a/qutebrowser/browser/webengine/darkmode.py b/qutebrowser/browser/webengine/darkmode.py
index 88b71a8fe..536765efb 100644
--- a/qutebrowser/browser/webengine/darkmode.py
+++ b/qutebrowser/browser/webengine/darkmode.py
@@ -205,14 +205,14 @@ class _Setting:
 
     option: str
     chromium_key: str
-    mapping: Optional[Mapping[Any, Union[str, int, None]]] = None
+    mapping: Mapping[Any, str | int | None] | None = None
 
     def _value_str(self, value: Any) -> str:
         if self.mapping is None:
             return str(value)
         return str(self.mapping[value])
 
-    def chromium_tuple(self, value: Any) -> Optional[tuple[str, str]]:
+    def chromium_tuple(self, value: Any) -> tuple[str, str] | None:
         """Get the Chromium key and value, or None if no value should be set."""
         if self.mapping is not None and self.mapping[value] is None:
             return None
@@ -244,7 +244,7 @@ class _Definition:
             *args: _Setting,
             mandatory: set[str],
             prefix: str,
-            switch_names: Mapping[Optional[str], str] = None,
+            switch_names: Mapping[str | None, str] = None,
     ) -> None:
         self._settings = args
         self.mandatory = mandatory
@@ -340,7 +340,7 @@ _DEFINITIONS[Variant.qt_66] = _DEFINITIONS[Variant.qt_64].copy_add_setting(
 _DEFINITIONS[Variant.qt_67] = _DEFINITIONS[Variant.qt_66].copy_remove_setting('enabled')
 
 
-_SettingValType = Union[str, usertypes.Unset]
+_SettingValType = str | usertypes.Unset
 _PREFERRED_COLOR_SCHEME_DEFINITIONS: MutableMapping[Variant, Mapping[_SettingValType, str]] = {
     Variant.qt_515_2: {
         # 0: no-preference (not exposed)
diff --git a/qutebrowser/browser/webengine/notification.py b/qutebrowser/browser/webengine/notification.py
index 9037ff214..c89abd5b2 100644
--- a/qutebrowser/browser/webengine/notification.py
+++ b/qutebrowser/browser/webengine/notification.py
@@ -154,7 +154,7 @@ class AbstractNotificationAdapter(QObject):
         self,
         qt_notification: "QWebEngineNotification",
         *,
-        replaces_id: Optional[int],
+        replaces_id: int | None,
     ) -> int:
         """Show the given notification.
 
@@ -197,7 +197,7 @@ class NotificationBridgePresenter(QObject):
         super().__init__(parent)
 
         self._active_notifications: dict[int, 'QWebEngineNotification'] = {}
-        self._adapter: Optional[AbstractNotificationAdapter] = None
+        self._adapter: AbstractNotificationAdapter | None = None
 
         config.instance.changed.connect(self._init_adapter)
 
@@ -300,7 +300,7 @@ class NotificationBridgePresenter(QObject):
     def _find_replaces_id(
         self,
         new_notification: "QWebEngineNotification",
-    ) -> Optional[int]:
+    ) -> int | None:
         """Find an existing notification to replace.
 
         If no notification should be replaced or the notification to be replaced was not
@@ -441,7 +441,7 @@ class SystrayNotificationAdapter(AbstractNotificationAdapter):
         self,
         qt_notification: "QWebEngineNotification",
         *,
-        replaces_id: Optional[int],
+        replaces_id: int | None,
     ) -> int:
         utils.unused(replaces_id)  # QSystemTray can only show one message
         self.close_id.emit(self.NOTIFICATION_ID)
@@ -503,7 +503,7 @@ class MessagesNotificationAdapter(AbstractNotificationAdapter):
         self,
         qt_notification: "QWebEngineNotification",
         *,
-        replaces_id: Optional[int],
+        replaces_id: int | None,
     ) -> int:
         markup = self._format_message(qt_notification)
         new_id = replaces_id if replaces_id is not None else next(self._id_gen)
@@ -563,7 +563,7 @@ class HerbeNotificationAdapter(AbstractNotificationAdapter):
         self,
         qt_notification: "QWebEngineNotification",
         *,
-        replaces_id: Optional[int],
+        replaces_id: int | None,
     ) -> int:
         if replaces_id is not None:
             self.on_web_closed(replaces_id)
@@ -647,11 +647,11 @@ class _ServerQuirks:
 
     """Quirks for certain DBus notification servers."""
 
-    spec_version: Optional[str] = None
+    spec_version: str | None = None
     avoid_actions: bool = False
     avoid_body_hyperlinks: bool = False
     escape_title: bool = False
-    icon_key: Optional[str] = None
+    icon_key: str | None = None
     skip_capabilities: bool = False
     wrong_replaces_id: bool = False
     no_padded_images: bool = False
@@ -778,7 +778,7 @@ class DBusNotificationAdapter(AbstractNotificationAdapter):
         name: str,
         vendor: str,
         ver: str,
-    ) -> Optional[_ServerQuirks]:
+    ) -> _ServerQuirks | None:
         """Find quirks to use based on the server information."""
         if (name, vendor) == ("notify-osd", "Canonical Ltd"):
             # Shows a dialog box instead of a notification bubble as soon as a
@@ -1009,7 +1009,7 @@ class DBusNotificationAdapter(AbstractNotificationAdapter):
         self,
         qt_notification: "QWebEngineNotification",
         *,
-        replaces_id: Optional[int],
+        replaces_id: int | None,
     ) -> int:
         """Shows a notification over DBus."""
         if replaces_id is None:
@@ -1045,7 +1045,7 @@ class DBusNotificationAdapter(AbstractNotificationAdapter):
         self._verify_notification_id(notification_id, replaces_id=replaces_id)
         return notification_id
 
-    def _convert_image(self, qimage: QImage) -> Optional[QDBusArgument]:
+    def _convert_image(self, qimage: QImage) -> QDBusArgument | None:
         """Convert a QImage to the structure DBus expects.
 
         https://specifications.freedesktop.org/notification-spec/latest/ar01s05.html#icons-and-images-formats
diff --git a/qutebrowser/browser/webengine/webengineelem.py b/qutebrowser/browser/webengine/webengineelem.py
index f65044998..033a7c831 100644
--- a/qutebrowser/browser/webengine/webengineelem.py
+++ b/qutebrowser/browser/webengine/webengineelem.py
@@ -29,7 +29,7 @@ class WebEngineElement(webelem.AbstractWebElement):
                  tab: 'webenginetab.WebEngineTab') -> None:
         super().__init__(tab)
         # Do some sanity checks on the data we get from JS
-        js_dict_types: dict[str, Union[type, tuple[type, ...]]] = {
+        js_dict_types: dict[str, type | tuple[type, ...]] = {
             'id': int,
             'text': str,
             'value': (str, int, float),
@@ -138,7 +138,7 @@ class WebEngineElement(webelem.AbstractWebElement):
                        composed: bool = False) -> None:
         self._js_call('dispatch_event', event, bubbles, cancelable, composed)
 
-    def caret_position(self) -> Optional[int]:
+    def caret_position(self) -> int | None:
         """Get the text caret position for the current element.
 
         If the element is not a text element, None is returned.
diff --git a/qutebrowser/browser/webengine/webengineinspector.py b/qutebrowser/browser/webengine/webengineinspector.py
index d37f41ba5..0d241f416 100644
--- a/qutebrowser/browser/webengine/webengineinspector.py
+++ b/qutebrowser/browser/webengine/webengineinspector.py
@@ -61,7 +61,7 @@ class WebEngineInspector(inspector.AbstractWebInspector):
                  parent: QWidget = None) -> None:
         super().__init__(splitter, win_id, parent)
         self._check_devtools_resources()
-        self._settings: Optional[webenginesettings.WebEngineSettings] = None
+        self._settings: webenginesettings.WebEngineSettings | None = None
 
     def _on_window_close_requested(self) -> None:
         """Called when the 'x' was clicked in the devtools."""
diff --git a/qutebrowser/browser/webengine/webenginesettings.py b/qutebrowser/browser/webengine/webenginesettings.py
index 6680fa637..5e898c25b 100644
--- a/qutebrowser/browser/webengine/webenginesettings.py
+++ b/qutebrowser/browser/webengine/webenginesettings.py
@@ -33,11 +33,11 @@ if TYPE_CHECKING:
 # The default QWebEngineProfile
 default_profile = cast(QWebEngineProfile, None)
 # The QWebEngineProfile used for private (off-the-record) windows
-private_profile: Optional[QWebEngineProfile] = None
+private_profile: QWebEngineProfile | None = None
 # The global WebEngineSettings object
 _global_settings = cast('WebEngineSettings', None)
 
-parsed_user_agent: Optional[websettings.UserAgent] = None
+parsed_user_agent: websettings.UserAgent | None = None
 
 _qute_scheme_handler = cast(webenginequtescheme.QuteSchemeHandler, None)
 _req_interceptor = cast('interceptor.RequestInterceptor', None)
@@ -223,7 +223,7 @@ class WebEngineSettings(websettings.AbstractSettings):
     }
 
     def set_unknown_url_scheme_policy(
-            self, policy: Union[str, usertypes.Unset]) -> None:
+            self, policy: str | usertypes.Unset) -> None:
         """Set the UnknownUrlSchemePolicy to use."""
         if isinstance(policy, usertypes.Unset):
             self._settings.resetUnknownUrlSchemePolicy()
@@ -231,7 +231,7 @@ class WebEngineSettings(websettings.AbstractSettings):
             new_value = self._UNKNOWN_URL_SCHEME_POLICY[policy]
             self._settings.setUnknownUrlSchemePolicy(new_value)
 
-    def _set_js_clipboard(self, value: Union[str, usertypes.Unset]) -> None:
+    def _set_js_clipboard(self, value: str | usertypes.Unset) -> None:
         attr_access = QWebEngineSettings.WebAttribute.JavascriptCanAccessClipboard
         attr_paste = QWebEngineSettings.WebAttribute.JavascriptCanPaste
 
diff --git a/qutebrowser/browser/webengine/webenginetab.py b/qutebrowser/browser/webengine/webenginetab.py
index cae8fa300..fb9346dde 100644
--- a/qutebrowser/browser/webengine/webenginetab.py
+++ b/qutebrowser/browser/webengine/webenginetab.py
@@ -92,7 +92,7 @@ class WebEnginePrinting(browsertab.AbstractPrinting):
 
 
 if machinery.IS_QT5:
-    _FindFlagType = Union[QWebEnginePage.FindFlag, QWebEnginePage.FindFlags]
+    _FindFlagType = QWebEnginePage.FindFlag | QWebEnginePage.FindFlags
 else:
     _FindFlagType = QWebEnginePage.FindFlag
 
@@ -1019,7 +1019,7 @@ class _Quirk:
         QWebEngineScript.InjectionPoint.DocumentCreation)
     world: QWebEngineScript.ScriptWorldId = QWebEngineScript.ScriptWorldId.MainWorld
     predicate: bool = True
-    name: Optional[str] = None
+    name: str | None = None
 
     def __post_init__(self):
         if self.name is None:
@@ -1375,7 +1375,7 @@ class WebEngineTab(browsertab.AbstractTab):
             log.misc.debug("run_js_async called on deleted tab")
             return
 
-        world_id_type = Union[QWebEngineScript.ScriptWorldId, int]
+        world_id_type = QWebEngineScript.ScriptWorldId | int
         if world is None:
             world_id: world_id_type = QWebEngineScript.ScriptWorldId.ApplicationWorld
         elif isinstance(world, int):
diff --git a/qutebrowser/browser/webengine/webview.py b/qutebrowser/browser/webengine/webview.py
index 362f00ca0..dd41ce74f 100644
--- a/qutebrowser/browser/webengine/webview.py
+++ b/qutebrowser/browser/webengine/webview.py
@@ -314,8 +314,8 @@ class WebEnginePage(QWebEnginePage):
     def chooseFiles(
         self,
         mode: QWebEnginePage.FileSelectionMode,
-        old_files: Iterable[Optional[str]],
-        accepted_mimetypes: Iterable[Optional[str]],
+        old_files: Iterable[str | None],
+        accepted_mimetypes: Iterable[str | None],
     ) -> list[str]:
         """Override chooseFiles to (optionally) invoke custom file uploader."""
         accepted_mimetypes_filtered = [m for m in accepted_mimetypes if m is not None]
diff --git a/qutebrowser/browser/webkit/certificateerror.py b/qutebrowser/browser/webkit/certificateerror.py
index 2c18af62e..7b1753ad8 100644
--- a/qutebrowser/browser/webkit/certificateerror.py
+++ b/qutebrowser/browser/webkit/certificateerror.py
@@ -21,7 +21,7 @@ class CertificateErrorWrapper(usertypes.AbstractCertificateErrorWrapper):
         self._reply = reply
         self._errors = tuple(errors)  # needs to be hashable
         try:
-            self._host_tpl: Optional[urlutils.HostTupleType] = urlutils.host_tuple(reply.url())
+            self._host_tpl: urlutils.HostTupleType | None = urlutils.host_tuple(reply.url())
         except ValueError:
             self._host_tpl = None
 
diff --git a/qutebrowser/browser/webkit/network/networkmanager.py b/qutebrowser/browser/webkit/network/networkmanager.py
index a950d4239..7494e8d2b 100644
--- a/qutebrowser/browser/webkit/network/networkmanager.py
+++ b/qutebrowser/browser/webkit/network/networkmanager.py
@@ -246,7 +246,7 @@ class NetworkManager(QNetworkAccessManager):
         errors = certificateerror.CertificateErrorWrapper(reply, qt_errors)
         log.network.debug("Certificate errors: {!r}".format(errors))
         try:
-            host_tpl: Optional[urlutils.HostTupleType] = urlutils.host_tuple(
+            host_tpl: urlutils.HostTupleType | None = urlutils.host_tuple(
                 reply.url())
         except ValueError:
             host_tpl = None
diff --git a/qutebrowser/browser/webkit/webkitelem.py b/qutebrowser/browser/webkit/webkitelem.py
index 6088a29d3..cfdcd8499 100644
--- a/qutebrowser/browser/webkit/webkitelem.py
+++ b/qutebrowser/browser/webkit/webkitelem.py
@@ -167,13 +167,13 @@ class WebKitElement(webelem.AbstractWebElement):
     def _parent(self) -> Optional['WebKitElement']:
         """Get the parent element of this element."""
         self._check_vanished()
-        elem = cast(Optional[QWebElement], self._elem.parent())
+        elem = cast(QWebElement | None, self._elem.parent())
         if elem is None or elem.isNull():
             return None
 
         return WebKitElement(elem, tab=self._tab)
 
-    def _rect_on_view_js(self) -> Optional[QRect]:
+    def _rect_on_view_js(self) -> QRect | None:
         """Javascript implementation for rect_on_view."""
         # FIXME:qtwebengine maybe we can reuse this?
         rects = self._elem.evaluateJavaScript("this.getClientRects()")
@@ -203,7 +203,7 @@ class WebKitElement(webelem.AbstractWebElement):
                 rect = QRect(int(rect["left"]), int(rect["top"]),
                              int(width), int(height))
 
-                frame = cast(Optional[QWebFrame], self._elem.webFrame())
+                frame = cast(QWebFrame | None, self._elem.webFrame())
                 while frame is not None:
                     # Translate to parent frames' position (scroll position
                     # is taken care of inside getClientRects)
@@ -214,7 +214,7 @@ class WebKitElement(webelem.AbstractWebElement):
 
         return None
 
-    def _rect_on_view_python(self, elem_geometry: Optional[QRect]) -> QRect:
+    def _rect_on_view_python(self, elem_geometry: QRect | None) -> QRect:
         """Python implementation for rect_on_view."""
         if elem_geometry is None:
             geometry = self._elem.geometry()
@@ -222,11 +222,11 @@ class WebKitElement(webelem.AbstractWebElement):
             geometry = elem_geometry
         rect = QRect(geometry)
 
-        frame = cast(Optional[QWebFrame], self._elem.webFrame())
+        frame = cast(QWebFrame | None, self._elem.webFrame())
         while frame is not None:
             rect.translate(frame.geometry().topLeft())
             rect.translate(frame.scrollPosition() * -1)
-            frame = cast(Optional[QWebFrame], frame.parentFrame())
+            frame = cast(QWebFrame | None, frame.parentFrame())
 
         return rect
 
@@ -320,7 +320,7 @@ class WebKitElement(webelem.AbstractWebElement):
         return all([visible_on_screen, visible_in_frame])
 
     def remove_blank_target(self) -> None:
-        elem: Optional[WebKitElement] = self
+        elem: WebKitElement | None = self
         for _ in range(5):
             if elem is None:
                 break
diff --git a/qutebrowser/browser/webkit/webkittab.py b/qutebrowser/browser/webkit/webkittab.py
index d89295440..98da8ca92 100644
--- a/qutebrowser/browser/webkit/webkittab.py
+++ b/qutebrowser/browser/webkit/webkittab.py
@@ -760,7 +760,7 @@ class WebKitElements(browsertab.AbstractElements):
         self.find_css('#' + elem_id, find_id_cb, error_cb=lambda exc: None)
 
     def find_focused(self, callback):
-        frame = cast(Optional[QWebFrame], self._widget.page().currentFrame())
+        frame = cast(QWebFrame | None, self._widget.page().currentFrame())
         if frame is None:
             callback(None)
             return
@@ -774,7 +774,7 @@ class WebKitElements(browsertab.AbstractElements):
     def find_at_pos(self, pos, callback):
         assert pos.x() >= 0
         assert pos.y() >= 0
-        frame = cast(Optional[QWebFrame], self._widget.page().frameAt(pos))
+        frame = cast(QWebFrame | None, self._widget.page().frameAt(pos))
         if frame is None:
             # This happens when we click inside the webview, but not actually
             # on the QWebPage - for example when clicking the scrollbar
@@ -930,7 +930,7 @@ class WebKitTab(browsertab.AbstractTab):
     def title(self):
         return self._widget.title()
 
-    def renderer_process_pid(self) -> Optional[int]:
+    def renderer_process_pid(self) -> int | None:
         return None
 
     @pyqtSlot()
diff --git a/qutebrowser/commands/command.py b/qutebrowser/commands/command.py
index 620f6a4ae..42608476e 100644
--- a/qutebrowser/commands/command.py
+++ b/qutebrowser/commands/command.py
@@ -25,12 +25,12 @@ class ArgInfo:
 
     """Information about an argument."""
 
-    value: Optional[usertypes.CommandValue] = None
+    value: usertypes.CommandValue | None = None
     hide: bool = False
-    metavar: Optional[str] = None
-    flag: Optional[str] = None
-    completion: Optional[Callable[..., completionmodel.CompletionModel]] = None
-    choices: Optional[list[str]] = None
+    metavar: str | None = None
+    flag: str | None = None
+    completion: Callable[..., completionmodel.CompletionModel] | None = None
+    choices: list[str] | None = None
 
 
 class Command:
diff --git a/qutebrowser/completion/completionwidget.py b/qutebrowser/completion/completionwidget.py
index c7e549f46..e41ca0b07 100644
--- a/qutebrowser/completion/completionwidget.py
+++ b/qutebrowser/completion/completionwidget.py
@@ -101,7 +101,7 @@ class CompletionView(QTreeView):
                  win_id: int,
                  parent: QWidget = None) -> None:
         super().__init__(parent)
-        self.pattern: Optional[str] = None
+        self.pattern: str | None = None
         self._win_id = win_id
         self._cmd = cmd
         self._active = False
diff --git a/qutebrowser/completion/models/__init__.py b/qutebrowser/completion/models/__init__.py
index a55a91215..186ed06cb 100644
--- a/qutebrowser/completion/models/__init__.py
+++ b/qutebrowser/completion/models/__init__.py
@@ -21,4 +21,4 @@ class BaseCategory(QAbstractItemModel):
 
     name: str
     columns_to_filter: Sequence[int]
-    delete_func: Optional[DeleteFuncType] = None
+    delete_func: DeleteFuncType | None = None
diff --git a/qutebrowser/completion/models/completionmodel.py b/qutebrowser/completion/models/completionmodel.py
index c0f6a86ff..5b7121a64 100644
--- a/qutebrowser/completion/models/completionmodel.py
+++ b/qutebrowser/completion/models/completionmodel.py
@@ -39,7 +39,7 @@ class CompletionModel(QAbstractItemModel):
         self.column_widths = column_widths
         self._categories: MutableSequence[BaseCategory] = []
 
-    def _cat_from_idx(self, index: QModelIndex) -> Optional[BaseCategory]:
+    def _cat_from_idx(self, index: QModelIndex) -> BaseCategory | None:
         """Return the category pointed to by the given index.
 
         Args:
@@ -128,7 +128,7 @@ class CompletionModel(QAbstractItemModel):
 
     else:
         @overload
-        def parent(self) -> Optional[QObject]:
+        def parent(self) -> QObject | None:
             ...
 
     def parent(self, index=None):
diff --git a/qutebrowser/completion/models/filepathcategory.py b/qutebrowser/completion/models/filepathcategory.py
index 0b2d887b8..6296b393c 100644
--- a/qutebrowser/completion/models/filepathcategory.py
+++ b/qutebrowser/completion/models/filepathcategory.py
@@ -87,7 +87,7 @@ class FilePathCategory(QAbstractListModel, BaseCategory):
             paths = self._glob(expanded)
             self._paths = sorted(self._contract_user(val, path) for path in paths)
 
-    def data(self, index: QModelIndex, role: int = Qt.ItemDataRole.DisplayRole) -> Optional[str]:
+    def data(self, index: QModelIndex, role: int = Qt.ItemDataRole.DisplayRole) -> str | None:
         """Implement abstract method in QAbstractListModel."""
         if role == Qt.ItemDataRole.DisplayRole and index.column() == 0:
             return self._paths[index.row()]
diff --git a/qutebrowser/completion/models/histcategory.py b/qutebrowser/completion/models/histcategory.py
index 5b79b4ade..04db2d9b3 100644
--- a/qutebrowser/completion/models/histcategory.py
+++ b/qutebrowser/completion/models/histcategory.py
@@ -26,12 +26,12 @@ class HistoryCategory(QSqlQueryModel, BaseCategory):
         super().__init__(parent=parent)
         self._database = database
         self.name = "History"
-        self._query: Optional[sql.Query] = None
+        self._query: sql.Query | None = None
 
         # advertise that this model filters by URL and title
         self.columns_to_filter = [0, 1]
         self.delete_func = delete_func
-        self._empty_prefix: Optional[str] = None
+        self._empty_prefix: str | None = None
 
     def _atime_expr(self):
         """If max_items is set, return an expression to limit the query."""
diff --git a/qutebrowser/components/braveadblock.py b/qutebrowser/components/braveadblock.py
index e140248a3..32cf23789 100644
--- a/qutebrowser/components/braveadblock.py
+++ b/qutebrowser/components/braveadblock.py
@@ -102,7 +102,7 @@ _RESOURCE_TYPE_STRINGS = {
 }
 
 
-def _resource_type_to_string(resource_type: Optional[ResourceType]) -> str:
+def _resource_type_to_string(resource_type: ResourceType | None) -> str:
     return _RESOURCE_TYPE_STRINGS.get(resource_type, "other")
 
 
@@ -174,8 +174,8 @@ class BraveAdBlocker:
     def _is_blocked(
         self,
         request_url: QUrl,
-        first_party_url: Optional[QUrl] = None,
-        resource_type: Optional[interceptor.ResourceType] = None,
+        first_party_url: QUrl | None = None,
+        resource_type: interceptor.ResourceType | None = None,
     ) -> bool:
         """Check whether the given request is blocked."""
         if not self.enabled:
diff --git a/qutebrowser/components/misccommands.py b/qutebrowser/components/misccommands.py
index b4eaa55d1..6d7ea9b40 100644
--- a/qutebrowser/components/misccommands.py
+++ b/qutebrowser/components/misccommands.py
@@ -34,7 +34,7 @@ _LOGGER = logging.getLogger('misc')
 
 @cmdutils.register(name='reload')
 @cmdutils.argument('tab', value=cmdutils.Value.count_tab)
-def reloadpage(tab: Optional[apitypes.Tab],
+def reloadpage(tab: apitypes.Tab | None,
                force: bool = False) -> None:
     """Reload the current/[count]th tab.
 
@@ -48,7 +48,7 @@ def reloadpage(tab: Optional[apitypes.Tab],
 
 @cmdutils.register()
 @cmdutils.argument('tab', value=cmdutils.Value.count_tab)
-def stop(tab: Optional[apitypes.Tab]) -> None:
+def stop(tab: apitypes.Tab | None) -> None:
     """Stop loading in the current/[count]th tab.
 
     Args:
@@ -88,9 +88,9 @@ def _print_pdf(tab: apitypes.Tab, path: pathlib.Path) -> None:
 @cmdutils.register(name='print')
 @cmdutils.argument('tab', value=cmdutils.Value.count_tab)
 @cmdutils.argument('pdf', flag='f', metavar='file')
-def printpage(tab: Optional[apitypes.Tab],
+def printpage(tab: apitypes.Tab | None,
               preview: bool = False, *,
-              pdf: Optional[pathlib.Path] = None) -> None:
+              pdf: pathlib.Path | None = None) -> None:
     """Print the current/[count]th tab.
 
     Args:
@@ -193,7 +193,7 @@ def insert_text(tab: apitypes.Tab, text: str) -> None:
     Args:
         text: The text to insert.
     """
-    def _insert_text_cb(elem: Optional[apitypes.WebElement]) -> None:
+    def _insert_text_cb(elem: apitypes.WebElement | None) -> None:
         if elem is None:
             message.error("No element focused!")
             return
@@ -207,7 +207,7 @@ def insert_text(tab: apitypes.Tab, text: str) -> None:
 
 
 def _wrap_find_at_pos(value: str, tab: apitypes.Tab,
-                      callback: Callable[[Optional[apitypes.WebElement]], None]
+                      callback: Callable[[apitypes.WebElement | None], None]
                       ) -> None:
     try:
         point = utils.parse_point(value)
@@ -257,7 +257,7 @@ def click_element(tab: apitypes.Tab, filter_: str, value: str = None, *,  # noqa
         except apitypes.WebElemError as e:
             message.error(str(e))
 
-    def single_cb(elem: Optional[apitypes.WebElement]) -> None:
+    def single_cb(elem: apitypes.WebElement | None) -> None:
         """Click a single element."""
         if elem is None:
             message.error(f"No element found {_FILTER_ERRORS[filter_](value)}!")
@@ -322,7 +322,7 @@ def debug_webaction(tab: apitypes.Tab, action: str, count: int = 1) -> None:
 
 @cmdutils.register()
 @cmdutils.argument('tab', value=cmdutils.Value.count_tab)
-def tab_mute(tab: Optional[apitypes.Tab]) -> None:
+def tab_mute(tab: apitypes.Tab | None) -> None:
     """Mute/Unmute the current/[count]th tab.
 
     Args:
diff --git a/qutebrowser/components/readlinecommands.py b/qutebrowser/components/readlinecommands.py
index a26f7ea4c..9732dca1c 100644
--- a/qutebrowser/components/readlinecommands.py
+++ b/qutebrowser/components/readlinecommands.py
@@ -24,7 +24,7 @@ class _ReadlineBridge:
     def __init__(self) -> None:
         self._deleted: MutableMapping[QLineEdit, str] = {}
 
-    def _widget(self) -> Optional[QLineEdit]:
+    def _widget(self) -> QLineEdit | None:
         """Get the currently active QLineEdit."""
         # FIXME add this to api.utils or so
         qapp = QApplication.instance()
diff --git a/qutebrowser/components/utils/blockutils.py b/qutebrowser/components/utils/blockutils.py
index 154c04317..6a106a802 100644
--- a/qutebrowser/components/utils/blockutils.py
+++ b/qutebrowser/components/utils/blockutils.py
@@ -47,7 +47,7 @@ class BlocklistDownloads(QObject):
     single_download_finished = pyqtSignal(object)  # arg: the file object
     all_downloads_finished = pyqtSignal(int)  # arg: download count
 
-    def __init__(self, urls: list[QUrl], parent: Optional[QObject] = None) -> None:
+    def __init__(self, urls: list[QUrl], parent: QObject | None = None) -> None:
         super().__init__(parent)
         self._urls = urls
 
diff --git a/qutebrowser/config/config.py b/qutebrowser/config/config.py
index d286bf733..1a9d9bc62 100644
--- a/qutebrowser/config/config.py
+++ b/qutebrowser/config/config.py
@@ -69,7 +69,7 @@ class change_filter:  # noqa: N801,N806 pylint: disable=invalid-name
                 not configdata.is_valid_prefix(self._option)):
             raise configexc.NoOptionError(self._option)
 
-    def check_match(self, option: Optional[str]) -> bool:
+    def check_match(self, option: str | None) -> bool:
         """Check if the given option matches the filter."""
         if option is None:
             # Called directly, not from a config change event.
@@ -153,7 +153,7 @@ class KeyConfig:
                 bindings[key] = binding
         return bindings
 
-    def _implied_cmd(self, cmdline: str) -> Optional[str]:
+    def _implied_cmd(self, cmdline: str) -> str | None:
         """Return cmdline, or the implied cmd if cmdline is a cmd-set-text."""
         try:
             results = parser.CommandParser().parse_all(cmdline)
@@ -198,7 +198,7 @@ class KeyConfig:
     def get_command(self,
                     key: keyutils.KeySequence,
                     mode: str,
-                    default: bool = False) -> Optional[str]:
+                    default: bool = False) -> str | None:
         """Get the command for a given key (or None)."""
         self._validate(key, mode)
         if default:
@@ -410,7 +410,7 @@ class Config(QObject):
 
     def get_obj_for_pattern(
             self, name: str, *,
-            pattern: Optional[urlmatch.UrlPattern]
+            pattern: urlmatch.UrlPattern | None
     ) -> Any:
         """Get the given setting as object (for YAML/config.py).
 
diff --git a/qutebrowser/config/configcommands.py b/qutebrowser/config/configcommands.py
index 9012cc2c4..44a4a0876 100644
--- a/qutebrowser/config/configcommands.py
+++ b/qutebrowser/config/configcommands.py
@@ -40,7 +40,7 @@ class ConfigCommands:
         except configexc.Error as e:
             raise cmdutils.CommandError(str(e))
 
-    def _parse_pattern(self, pattern: Optional[str]) -> Optional[urlmatch.UrlPattern]:
+    def _parse_pattern(self, pattern: str | None) -> urlmatch.UrlPattern | None:
         """Parse a pattern string argument to a pattern."""
         if pattern is None:
             return None
@@ -58,7 +58,7 @@ class ConfigCommands:
         except keyutils.KeyParseError as e:
             raise cmdutils.CommandError(str(e))
 
-    def _print_value(self, option: str, pattern: Optional[urlmatch.UrlPattern]) -> None:
+    def _print_value(self, option: str, pattern: urlmatch.UrlPattern | None) -> None:
         """Print the value of the given option."""
         with self._handle_config_error():
             value = self._config.get_str(option, pattern=pattern)
@@ -474,7 +474,7 @@ class ConfigCommands:
             raise cmdutils.CommandError("{} already exists - use --force to "
                                         "overwrite!".format(filename))
 
-        options: list[tuple[Optional[urlmatch.UrlPattern], configdata.Option, Any]] = []
+        options: list[tuple[urlmatch.UrlPattern | None, configdata.Option, Any]] = []
         if defaults:
             options = [(None, opt, opt.default)
                        for _name, opt in sorted(configdata.DATA.items())]
diff --git a/qutebrowser/config/configdata.py b/qutebrowser/config/configdata.py
index d939f7ea6..ec09a0a14 100644
--- a/qutebrowser/config/configdata.py
+++ b/qutebrowser/config/configdata.py
@@ -21,7 +21,7 @@ from qutebrowser.misc import debugcachestats
 DATA = cast(Mapping[str, 'Option'], None)
 MIGRATIONS = cast('Migrations', None)
 
-_BackendDict = Mapping[str, Union[str, bool]]
+_BackendDict = Mapping[str, str | bool]
 
 
 @dataclasses.dataclass(order=True)
@@ -36,7 +36,7 @@ class Option:
     typ: configtypes.BaseType
     default: Any
     backends: Iterable[usertypes.Backend]
-    raw_backends: Optional[Mapping[str, bool]]
+    raw_backends: Mapping[str, bool] | None
     description: str
     supports_pattern: bool = False
     restart: bool = False
@@ -71,7 +71,7 @@ def _raise_invalid_node(name: str, what: str, node: Any) -> NoReturn:
 
 def _parse_yaml_type(
         name: str,
-        node: Union[str, Mapping[str, Any]],
+        node: str | Mapping[str, Any],
 ) -> configtypes.BaseType:
     if isinstance(node, str):
         # e.g:
@@ -157,7 +157,7 @@ def _parse_yaml_backends_dict(
 
 def _parse_yaml_backends(
         name: str,
-        node: Union[None, str, _BackendDict],
+        node: None | str | _BackendDict,
 ) -> Sequence[usertypes.Backend]:
     """Parse a backend node in the yaml.
 
diff --git a/qutebrowser/config/configexc.py b/qutebrowser/config/configexc.py
index 85845f6fc..96216616b 100644
--- a/qutebrowser/config/configexc.py
+++ b/qutebrowser/config/configexc.py
@@ -33,7 +33,7 @@ class BackendError(Error):
     def __init__(
             self, name: str,
             backend: usertypes.Backend,
-            raw_backends: Optional[Mapping[str, bool]]
+            raw_backends: Mapping[str, bool] | None
     ) -> None:
         if raw_backends is None or not raw_backends[backend.name]:
             msg = ("The {} setting is not available with the {} backend!"
@@ -63,7 +63,7 @@ class ValidationError(Error):
         msg: Additional error message.
     """
 
-    def __init__(self, value: Any, msg: Union[str, Exception]) -> None:
+    def __init__(self, value: Any, msg: str | Exception) -> None:
         super().__init__("Invalid value '{}' - {}".format(value, msg))
         self.option = None
 
@@ -111,8 +111,8 @@ class ConfigErrorDesc:
     """
 
     text: str
-    exception: Union[str, Exception]
-    traceback: Optional[str] = None
+    exception: str | Exception
+    traceback: str | None = None
 
     def __str__(self) -> str:
         if self.traceback:
diff --git a/qutebrowser/config/configfiles.py b/qutebrowser/config/configfiles.py
index 3fcdd53d8..f2181cd72 100644
--- a/qutebrowser/config/configfiles.py
+++ b/qutebrowser/config/configfiles.py
@@ -114,7 +114,7 @@ class StateConfig(configparser.ConfigParser):
             return False
         return True
 
-    def _qtwe_versions(self) -> Optional[version.WebEngineVersions]:
+    def _qtwe_versions(self) -> version.WebEngineVersions | None:
         """Get the QtWebEngine versions."""
         if not self._has_webengine():
             return None
@@ -758,7 +758,7 @@ class ConfigAPI:
             urlpattern = urlmatch.UrlPattern(pattern) if pattern else None
             self._config.set_obj(name, value, pattern=urlpattern)
 
-    def bind(self, key: str, command: Optional[str], mode: str = 'normal') -> None:
+    def bind(self, key: str, command: str | None, mode: str = 'normal') -> None:
         """Bind a key to a command, with an optional key mode."""
         with self._handle_error(f"binding '{key}'"):
             seq = keyutils.KeySequence.parse(key)
@@ -805,12 +805,12 @@ class ConfigPyWriter:
             self,
             options: list[
                 tuple[
-                    Optional[urlmatch.UrlPattern],
+                    urlmatch.UrlPattern | None,
                     configdata.Option,
                     Any
                 ]
             ],
-            bindings: MutableMapping[str, Mapping[str, Optional[str]]],
+            bindings: MutableMapping[str, Mapping[str, str | None]],
             *,
             commented: bool,
     ) -> None:
diff --git a/qutebrowser/config/configinit.py b/qutebrowser/config/configinit.py
index a08ddb619..4c783f89a 100644
--- a/qutebrowser/config/configinit.py
+++ b/qutebrowser/config/configinit.py
@@ -20,7 +20,7 @@ from qutebrowser.misc import msgbox, objects, savemanager
 
 
 # Error which happened during init, so we can show a message box.
-_init_errors: Optional[configexc.ConfigFileErrors] = None
+_init_errors: configexc.ConfigFileErrors | None = None
 
 
 def early_init(args: argparse.Namespace) -> None:
diff --git a/qutebrowser/config/configtypes.py b/qutebrowser/config/configtypes.py
index a64600652..ea2a8517c 100644
--- a/qutebrowser/config/configtypes.py
+++ b/qutebrowser/config/configtypes.py
@@ -66,13 +66,13 @@ BOOLEAN_STATES = {'1': True, 'yes': True, 'true': True, 'on': True,
                   '0': False, 'no': False, 'false': False, 'off': False}
 
 
-_Completions = Optional[Iterable[tuple[str, str]]]
-_StrUnset = Union[str, usertypes.Unset]
-_UnsetNone = Union[None, usertypes.Unset]
-_StrUnsetNone = Union[str, _UnsetNone]
+_Completions = _Completions = Iterable[tuple[str, str]] | None
+_StrUnset = str | usertypes.Unset
+_UnsetNone = None | usertypes.Unset
+_StrUnsetNone = str | _UnsetNone
 
 
-def _validate_encoding(encoding: Optional[str], value: str) -> None:
+def _validate_encoding(encoding: str | None, value: str) -> None:
     """Check if the given value fits into the given encoding.
 
     Raises ValidationError if not.
@@ -101,11 +101,7 @@ class ValidValues:
 
     def __init__(
             self,
-            *values: Union[
-                str,
-                dict[str, Optional[str]],
-                tuple[str, Optional[str]],
-            ],
+            *values: str | dict[str, str | None] | tuple[str, str | None],
             generate_docs: bool = True,
             others_permitted: bool = False
     ) -> None:
@@ -178,19 +174,19 @@ class BaseType:
     ) -> None:
         self._completions = completions
         self.none_ok = none_ok
-        self.valid_values: Optional[ValidValues] = None
+        self.valid_values: ValidValues | None = None
 
     def get_name(self) -> str:
         """Get a name for the type for documentation."""
         return self.__class__.__name__
 
-    def get_valid_values(self) -> Optional[ValidValues]:
+    def get_valid_values(self) -> ValidValues | None:
         """Get the type's valid values for documentation."""
         return self.valid_values
 
     def _basic_py_validation(
             self, value: Any,
-            pytype: Union[type, tuple[type, ...]]) -> None:
+            pytype: type | tuple[type, ...]) -> None:
         """Do some basic validation for Python values (emptyness, type).
 
         Arguments:
@@ -356,7 +352,7 @@ class MappingType(BaseType):
         MAPPING: A mapping from config values to (translated_value, docs) tuples.
     """
 
-    MAPPING: dict[str, tuple[Any, Optional[str]]] = {}
+    MAPPING: dict[str, tuple[Any, str | None]] = {}
 
     def __init__(
             self, *,
@@ -505,10 +501,10 @@ class List(BaseType):
             name += " of " + self.valtype.get_name()
         return name
 
-    def get_valid_values(self) -> Optional[ValidValues]:
+    def get_valid_values(self) -> ValidValues | None:
         return self.valtype.get_valid_values()
 
-    def from_str(self, value: str) -> Optional[list]:
+    def from_str(self, value: str) -> list | None:
         self._basic_str_validation(value)
         if not value:
             return None
@@ -523,15 +519,15 @@ class List(BaseType):
         self.to_py(yaml_val)
         return yaml_val
 
-    def from_obj(self, value: Optional[list]) -> list:
+    def from_obj(self, value: list | None) -> list:
         if value is None:
             return []
         return [self.valtype.from_obj(v) for v in value]
 
     def to_py(
             self,
-            value: Union[list, usertypes.Unset]
-    ) -> Union[list, usertypes.Unset]:
+            value: list | usertypes.Unset
+    ) -> list | usertypes.Unset:
         self._basic_py_validation(value, list)
         if isinstance(value, usertypes.Unset):
             return value
@@ -610,7 +606,7 @@ class ListOrValue(BaseType):
     def get_name(self) -> str:
         return self.listtype.get_name() + ', or ' + self.valtype.get_name()
 
-    def get_valid_values(self) -> Optional[ValidValues]:
+    def get_valid_values(self) -> ValidValues | None:
         return self.valtype.get_valid_values()
 
     def from_str(self, value: str) -> Any:
@@ -659,7 +655,7 @@ class FlagList(List):
     the valid values of the setting.
     """
 
-    combinable_values: Optional[Sequence] = None
+    combinable_values: Sequence | None = None
 
     _show_valtype = False
 
@@ -685,8 +681,8 @@ class FlagList(List):
 
     def to_py(
             self,
-            value: Union[usertypes.Unset, list],
-    ) -> Union[usertypes.Unset, list]:
+            value: usertypes.Unset | list,
+    ) -> usertypes.Unset | list:
         vals = super().to_py(value)
         if not isinstance(vals, usertypes.Unset):
             self._check_duplicates(vals)
@@ -737,12 +733,12 @@ class Bool(BaseType):
         super().__init__(none_ok=none_ok, completions=completions)
         self.valid_values = ValidValues('true', 'false', generate_docs=False)
 
-    def to_py(self, value: Union[bool, str, None]) -> Optional[bool]:
+    def to_py(self, value: bool | str | None) -> bool | None:
         self._basic_py_validation(value, bool)
         assert not isinstance(value, str)
         return value
 
-    def from_str(self, value: str) -> Optional[bool]:
+    def from_str(self, value: str) -> bool | None:
         self._basic_str_validation(value)
         if not value:
             return None
@@ -752,7 +748,7 @@ class Bool(BaseType):
         except KeyError:
             raise configexc.ValidationError(value, "must be a boolean!")
 
-    def to_str(self, value: Optional[bool]) -> str:
+    def to_str(self, value: bool | None) -> str:
         mapping = {
             None: '',
             True: 'true',
@@ -774,7 +770,7 @@ class BoolAsk(Bool):
         self.valid_values = ValidValues('true', 'false', 'ask')
 
     def to_py(self,  # type: ignore[override]
-              value: Union[bool, str]) -> Union[bool, str, None]:
+              value: bool | str) -> bool | str | None:
         # basic validation unneeded if it's == 'ask' and done by Bool if we
         # call super().to_py
         if isinstance(value, str) and value.lower() == 'ask':
@@ -782,14 +778,14 @@ class BoolAsk(Bool):
         return super().to_py(value)
 
     def from_str(self,  # type: ignore[override]
-                 value: str) -> Union[bool, str, None]:
+                 value: str) -> bool | str | None:
         # basic validation unneeded if it's == 'ask' and done by Bool if we
         # call super().from_str
         if value.lower() == 'ask':
             return 'ask'
         return super().from_str(value)
 
-    def to_str(self, value: Union[bool, str, None]) -> str:
+    def to_str(self, value: bool | str | None) -> str:
         mapping = {
             None: '',
             True: 'true',
@@ -826,8 +822,8 @@ class _Numeric(BaseType):  # pylint: disable=abstract-method
                                  .format(self.minval, self.maxval))
 
     def _parse_bound(
-            self, bound: Union[None, str, int, float]
-    ) -> Union[None, int, float]:
+            self, bound: None | str | int | float
+    ) -> None | int | float:
         """Get a numeric bound from a string like 'maxint'."""
         if bound == 'maxint':
             return qtutils.MAXVALS['int']
@@ -839,7 +835,7 @@ class _Numeric(BaseType):  # pylint: disable=abstract-method
             return bound
 
     def _validate_bounds(self,
-                         value: Union[int, float, _UnsetNone],
+                         value: int | float | _UnsetNone,
                          suffix: str = '') -> None:
         """Validate self.minval and self.maxval."""
         if value is None:
@@ -855,7 +851,7 @@ class _Numeric(BaseType):  # pylint: disable=abstract-method
         elif not self.zero_ok and value == 0:
             raise configexc.ValidationError(value, "must not be 0!")
 
-    def to_str(self, value: Union[None, int, float]) -> str:
+    def to_str(self, value: None | int | float) -> str:
         if value is None:
             return ''
         return str(value)
@@ -869,7 +865,7 @@ class Int(_Numeric):
 
     """Base class for an integer setting."""
 
-    def from_str(self, value: str) -> Optional[int]:
+    def from_str(self, value: str) -> int | None:
         self._basic_str_validation(value)
         if not value:
             return None
@@ -881,7 +877,7 @@ class Int(_Numeric):
         self.to_py(intval)
         return intval
 
-    def to_py(self, value: Union[int, _UnsetNone]) -> Union[int, _UnsetNone]:
+    def to_py(self, value: int | _UnsetNone) -> int | _UnsetNone:
         self._basic_py_validation(value, int)
         self._validate_bounds(value)
         return value
@@ -891,7 +887,7 @@ class Float(_Numeric):
 
     """Base class for a float setting."""
 
-    def from_str(self, value: str) -> Optional[float]:
+    def from_str(self, value: str) -> float | None:
         self._basic_str_validation(value)
         if not value:
             return None
@@ -905,8 +901,8 @@ class Float(_Numeric):
 
     def to_py(
             self,
-            value: Union[int, float, _UnsetNone],
-    ) -> Union[int, float, _UnsetNone]:
+            value: int | float | _UnsetNone,
+    ) -> int | float | _UnsetNone:
         self._basic_py_validation(value, (int, float))
         self._validate_bounds(value)
         return value
@@ -918,8 +914,8 @@ class Perc(_Numeric):
 
     def to_py(
             self,
-            value: Union[float, int, str, _UnsetNone]
-    ) -> Union[float, int, _UnsetNone]:
+            value: float | int | str | _UnsetNone
+    ) -> float | int | _UnsetNone:
         self._basic_py_validation(value, (float, int, str))
         if isinstance(value, usertypes.Unset):
             return value
@@ -936,7 +932,7 @@ class Perc(_Numeric):
         self._validate_bounds(value, suffix='%')
         return value
 
-    def to_str(self, value: Union[None, float, int, str]) -> str:
+    def to_str(self, value: None | float | int | str) -> str:
         if value is None:
             return ''
         elif isinstance(value, str):
@@ -978,7 +974,7 @@ class PercOrInt(_Numeric):
             raise ValueError("minperc ({}) needs to be <= maxperc "
                              "({})!".format(self.minperc, self.maxperc))
 
-    def from_str(self, value: str) -> Union[None, str, int]:
+    def from_str(self, value: str) -> None | str | int:
         self._basic_str_validation(value)
         if not value:
             return None
@@ -995,7 +991,7 @@ class PercOrInt(_Numeric):
         self.to_py(intval)
         return intval
 
-    def to_py(self, value: Union[None, str, int]) -> Union[None, str, int]:
+    def to_py(self, value: None | str | int) -> None | str | int:
         """Expect a value like '42%' as string, or 23 as int."""
         self._basic_py_validation(value, (int, str))
         if value is None:
@@ -1110,7 +1106,7 @@ class QtColor(BaseType):
         except ValueError:
             raise configexc.ValidationError(val, "must be a valid color value")
 
-    def to_py(self, value: _StrUnset) -> Union[_UnsetNone, QColor]:
+    def to_py(self, value: _StrUnset) -> _UnsetNone | QColor:
         self._basic_py_validation(value, str)
         if isinstance(value, usertypes.Unset):
             return value
@@ -1193,8 +1189,8 @@ class FontBase(BaseType):
     """Base class for Font/FontFamily."""
 
     # Gets set when the config is initialized.
-    default_family: Optional[str] = None
-    default_size: Optional[str] = None
+    default_family: str | None = None
+    default_size: str | None = None
     font_regex = re.compile(r"""
         (
             (
@@ -1334,8 +1330,8 @@ class Regex(BaseType):
 
     def to_py(
             self,
-            value: Union[str, Pattern[str], usertypes.Unset]
-    ) -> Union[_UnsetNone, Pattern[str]]:
+            value: str | Pattern[str] | usertypes.Unset
+    ) -> _UnsetNone | Pattern[str]:
         """Get a compiled regex from either a string or a regex object."""
         self._basic_py_validation(value, (str, self._regex_type))
         if isinstance(value, usertypes.Unset):
@@ -1347,7 +1343,7 @@ class Regex(BaseType):
         else:
             return value
 
-    def to_str(self, value: Union[None, str, Pattern[str]]) -> str:
+    def to_str(self, value: None | str | Pattern[str]) -> str:
         if value is None:
             return ''
         elif isinstance(value, self._regex_type):
@@ -1396,7 +1392,7 @@ class Dict(BaseType):
             raise configexc.ValidationError(
                 value, "Required keys {}".format(self.required_keys))
 
-    def from_str(self, value: str) -> Optional[dict]:
+    def from_str(self, value: str) -> dict | None:
         self._basic_str_validation(value)
         if not value:
             return None
@@ -1411,7 +1407,7 @@ class Dict(BaseType):
         self.to_py(yaml_val)
         return yaml_val
 
-    def from_obj(self, value: Optional[dict]) -> dict:
+    def from_obj(self, value: dict | None) -> dict:
         if value is None:
             return {}
 
@@ -1429,8 +1425,8 @@ class Dict(BaseType):
 
     def to_py(
             self,
-            value: Union[dict, _UnsetNone]
-    ) -> Union[dict, usertypes.Unset]:
+            value: dict | _UnsetNone
+    ) -> dict | usertypes.Unset:
         self._basic_py_validation(value, dict)
         if isinstance(value, usertypes.Unset):
             return value
@@ -1606,8 +1602,8 @@ class ShellCommand(List):
 
     def to_py(
             self,
-            value: Union[list, usertypes.Unset],
-    ) -> Union[list, usertypes.Unset]:
+            value: list | usertypes.Unset,
+    ) -> list | usertypes.Unset:
         py_value = super().to_py(value)
         if isinstance(py_value, usertypes.Unset):
             return py_value
@@ -1646,7 +1642,7 @@ class Proxy(BaseType):
     def to_py(
             self,
             value: _StrUnset
-    ) -> Union[_UnsetNone, QNetworkProxy, _SystemProxy, pac.PACFetcher]:
+    ) -> _UnsetNone | QNetworkProxy | _SystemProxy | pac.PACFetcher:
         self._basic_py_validation(value, str)
         if isinstance(value, usertypes.Unset):
             return value
@@ -1719,7 +1715,7 @@ class FuzzyUrl(BaseType):
 
     """A URL which gets interpreted as search if needed."""
 
-    def to_py(self, value: _StrUnset) -> Union[QUrl, _UnsetNone]:
+    def to_py(self, value: _StrUnset) -> QUrl | _UnsetNone:
         self._basic_py_validation(value, str)
         if isinstance(value, usertypes.Unset):
             return value
@@ -1764,8 +1760,8 @@ class Padding(Dict):
 
     def to_py(  # type: ignore[override]
             self,
-            value: Union[dict, _UnsetNone],
-    ) -> Union[usertypes.Unset, PaddingValues]:
+            value: dict | _UnsetNone,
+    ) -> usertypes.Unset | PaddingValues:
         d = super().to_py(value)
         if isinstance(d, usertypes.Unset):
             return d
@@ -1842,7 +1838,7 @@ class Url(BaseType):
 
     """A URL as a string."""
 
-    def to_py(self, value: _StrUnset) -> Union[_UnsetNone, QUrl]:
+    def to_py(self, value: _StrUnset) -> _UnsetNone | QUrl:
         self._basic_py_validation(value, str)
         if isinstance(value, usertypes.Unset):
             return value
@@ -1917,8 +1913,8 @@ class ConfirmQuit(FlagList):
 
     def to_py(
             self,
-            value: Union[usertypes.Unset, list],
-    ) -> Union[list, usertypes.Unset]:
+            value: usertypes.Unset | list,
+    ) -> list | usertypes.Unset:
         values = super().to_py(value)
         if isinstance(values, usertypes.Unset):
             return values
@@ -1979,7 +1975,7 @@ class Key(BaseType):
     def to_py(
             self,
             value: _StrUnset
-    ) -> Union[_UnsetNone, keyutils.KeySequence]:
+    ) -> _UnsetNone | keyutils.KeySequence:
         self._basic_py_validation(value, str)
         if isinstance(value, usertypes.Unset):
             return value
@@ -2004,7 +2000,7 @@ class UrlPattern(BaseType):
     def to_py(
             self,
             value: _StrUnset
-    ) -> Union[_UnsetNone, urlmatch.UrlPattern]:
+    ) -> _UnsetNone | urlmatch.UrlPattern:
         self._basic_py_validation(value, str)
         if isinstance(value, usertypes.Unset):
             return value
diff --git a/qutebrowser/config/configutils.py b/qutebrowser/config/configutils.py
index 2aaef7a97..c36acee1a 100644
--- a/qutebrowser/config/configutils.py
+++ b/qutebrowser/config/configutils.py
@@ -36,7 +36,7 @@ class ScopedValue:
     id_gen = itertools.count(0)
 
     def __init__(self, value: Any,
-                 pattern: Optional[urlmatch.UrlPattern],
+                 pattern: urlmatch.UrlPattern | None,
                  hide_userconfig: bool = False) -> None:
         self.value = value
         self.pattern = pattern
@@ -69,7 +69,7 @@ class Values:
         _domain_map: A mapping from hostnames to all associated ScopedValues.
     """
 
-    _VmapKeyType = Optional[urlmatch.UrlPattern]
+    _VmapKeyType = urlmatch.UrlPattern | None
 
     def __init__(self,
                  opt: 'configdata.Option',
@@ -79,7 +79,7 @@ class Values:
             Values._VmapKeyType, ScopedValue] = collections.OrderedDict()
         # A map from domain parts to rules that fall under them.
         self._domain_map: dict[
-            Optional[str], set[ScopedValue]] = collections.defaultdict(set)
+            str | None, set[ScopedValue]] = collections.defaultdict(set)
 
         for scoped in values:
             self._add_scoped(scoped)
@@ -130,7 +130,7 @@ class Values:
         return bool(self._vmap)
 
     def _check_pattern_support(
-            self, arg: Union[urlmatch.UrlPattern, QUrl, None]) -> None:
+            self, arg: urlmatch.UrlPattern | QUrl | None) -> None:
         """Make sure patterns are supported if one was given."""
         if arg is not None and not self.opt.supports_pattern:
             raise configexc.NoPatternError(self.opt.name)
@@ -225,7 +225,7 @@ class Values:
         return self._get_fallback(fallback)
 
     def get_for_pattern(self,
-                        pattern: Optional[urlmatch.UrlPattern], *,
+                        pattern: urlmatch.UrlPattern | None, *,
                         fallback: bool = True) -> Any:
         """Get a value only if it's been overridden for the given pattern.
 
diff --git a/qutebrowser/config/qtargs.py b/qutebrowser/config/qtargs.py
index 9341b2004..47afe75aa 100644
--- a/qutebrowser/config/qtargs.py
+++ b/qutebrowser/config/qtargs.py
@@ -213,7 +213,7 @@ def _webengine_locales_path() -> pathlib.Path:
 def _get_lang_override(
         webengine_version: utils.VersionNumber,
         locale_name: str
-) -> Optional[str]:
+) -> str | None:
     """Get a --lang switch to override Qt's locale handling.
 
     This is needed as a WORKAROUND for https://bugreports.qt.io/browse/QTBUG-91715
@@ -290,16 +290,15 @@ def _qtwebengine_args(
     yield from _qtwebengine_settings_args(versions)
 
 
-_SettingValueType = Union[
-    str,
-    Callable[
-        [
-            version.WebEngineVersions,
-        ],
-        Optional[str],
-    ],
-]
-_WEBENGINE_SETTINGS: dict[str, dict[Any, Optional[_SettingValueType]]] = {
+_SettingValueType = (
+    str
+    | Callable[
+        [version.WebEngineVersions],
+        str | None,
+    ]
+)
+
+_WEBENGINE_SETTINGS: dict[str, dict[Any, _SettingValueType | None]] = {
     'qt.force_software_rendering': {
         'software-opengl': None,
         'qt-quick': None,
diff --git a/qutebrowser/config/stylesheet.py b/qutebrowser/config/stylesheet.py
index 258e26002..d5b7de7df 100644
--- a/qutebrowser/config/stylesheet.py
+++ b/qutebrowser/config/stylesheet.py
@@ -58,7 +58,7 @@ class _StyleSheetObserver(QObject):
     """
 
     def __init__(self, obj: QWidget,
-                 stylesheet: Optional[str], update: bool) -> None:
+                 stylesheet: str | None, update: bool) -> None:
         super().__init__()
         self._obj = obj
         self._update = update
@@ -72,7 +72,7 @@ class _StyleSheetObserver(QObject):
             self._stylesheet = stylesheet
 
         if update:
-            self._options: Optional[frozenset[str]] = jinja.template_config_variables(
+            self._options: frozenset[str] | None = jinja.template_config_variables(
                 self._stylesheet)
         else:
             self._options = None
diff --git a/qutebrowser/config/websettings.py b/qutebrowser/config/websettings.py
index 3913cb24e..5b9d15b56 100644
--- a/qutebrowser/config/websettings.py
+++ b/qutebrowser/config/websettings.py
@@ -32,7 +32,7 @@ class UserAgent:
     upstream_browser_key: str
     upstream_browser_version: str
     qt_key: str
-    qt_version: Optional[str]
+    qt_version: str | None
 
     @property
     def upstream_browser_version_short(self) -> str:
@@ -123,7 +123,7 @@ class AbstractSettings:
         info = self._ATTRIBUTES[name]
         return self._settings.testAttribute(info.attributes[0])
 
-    def set_font_size(self, name: str, value: Union[int, usertypes.Unset]) -> None:
+    def set_font_size(self, name: str, value: int | usertypes.Unset) -> None:
         """Set the given QWebSettings/QWebEngineSettings font size."""
         family = self._FONT_SIZES[name]
         if value is usertypes.UNSET:
@@ -134,7 +134,7 @@ class AbstractSettings:
     def set_font_family(
         self,
         name: str,
-        value: Union[str, None, usertypes.Unset],
+        value: str | None | usertypes.Unset,
     ) -> None:
         """Set the given QWebSettings/QWebEngineSettings font family.
 
@@ -152,7 +152,7 @@ class AbstractSettings:
         else:
             self._settings.setFontFamily(family, value)
 
-    def set_default_text_encoding(self, encoding: Union[str, usertypes.Unset]) -> None:
+    def set_default_text_encoding(self, encoding: str | usertypes.Unset) -> None:
         """Set the default text encoding to use."""
         assert encoding is not usertypes.UNSET  # unclear how to reset
         self._settings.setDefaultTextEncoding(encoding)
diff --git a/qutebrowser/extensions/interceptors.py b/qutebrowser/extensions/interceptors.py
index 31fc94e0d..5432c3f5c 100644
--- a/qutebrowser/extensions/interceptors.py
+++ b/qutebrowser/extensions/interceptors.py
@@ -55,7 +55,7 @@ class Request:
     """A request which can be intercepted/blocked."""
 
     #: The URL of the page being shown.
-    first_party_url: Optional[QUrl]
+    first_party_url: QUrl | None
 
     #: The URL of the file being requested.
     request_url: QUrl
@@ -63,7 +63,7 @@ class Request:
     is_blocked: bool = False
 
     #: The resource type of the request. None if not supported on this backend.
-    resource_type: Optional[ResourceType] = None
+    resource_type: ResourceType | None = None
 
     def block(self) -> None:
         """Block this request."""
diff --git a/qutebrowser/extensions/loader.py b/qutebrowser/extensions/loader.py
index a6917be35..22c5b031c 100644
--- a/qutebrowser/extensions/loader.py
+++ b/qutebrowser/extensions/loader.py
@@ -47,10 +47,10 @@ class ModuleInfo:
     """
 
     skip_hooks: bool = False
-    init_hook: Optional[InitHookType] = None
+    init_hook: InitHookType | None = None
     config_changed_hooks: list[
         tuple[
-            Optional[str],
+            str | None,
             ConfigChangedHookType,
         ]
     ] = dataclasses.field(default_factory=list)
diff --git a/qutebrowser/keyinput/basekeyparser.py b/qutebrowser/keyinput/basekeyparser.py
index c97570369..cd796cc47 100644
--- a/qutebrowser/keyinput/basekeyparser.py
+++ b/qutebrowser/keyinput/basekeyparser.py
@@ -25,7 +25,7 @@ class MatchResult:
     """The result of matching a keybinding."""
 
     match_type: QKeySequence.SequenceMatch
-    command: Optional[str]
+    command: str | None
     sequence: keyutils.KeySequence
 
     def __post_init__(self) -> None:
@@ -63,7 +63,7 @@ class BindingTrie:
 
     def __init__(self) -> None:
         self.children: MutableMapping[keyutils.KeyInfo, BindingTrie] = {}
-        self.command: Optional[str] = None
+        self.command: str | None = None
 
     def __setitem__(self, sequence: keyutils.KeySequence,
                     command: str) -> None:
diff --git a/qutebrowser/keyinput/eventfilter.py b/qutebrowser/keyinput/eventfilter.py
index a9e7e78aa..dfff2e62e 100644
--- a/qutebrowser/keyinput/eventfilter.py
+++ b/qutebrowser/keyinput/eventfilter.py
@@ -62,7 +62,7 @@ class EventFilter(QObject):
             # No window available yet, or not a MainWindow
             return False
 
-    def eventFilter(self, obj: Optional[QObject], event: Optional[QEvent]) -> bool:
+    def eventFilter(self, obj: QObject | None, event: QEvent | None) -> bool:
         """Handle an event.
 
         Args:
diff --git a/qutebrowser/keyinput/keyutils.py b/qutebrowser/keyinput/keyutils.py
index 8bb63bbe6..31f11e263 100644
--- a/qutebrowser/keyinput/keyutils.py
+++ b/qutebrowser/keyinput/keyutils.py
@@ -52,7 +52,7 @@ _MODIFIER_MAP = {
 }
 
 try:
-    _NIL_KEY: Union[Qt.Key, int] = Qt.Key(0)
+    _NIL_KEY: Qt.Key | int = Qt.Key(0)
 except ValueError:
     # WORKAROUND for
     # https://www.riverbankcomputing.com/pipermail/pyqt/2022-April/044607.html
@@ -63,7 +63,7 @@ if machinery.IS_QT6:
     _ModifierType = Qt.KeyboardModifier
 else:
     _KeyInfoType = int
-    _ModifierType = Union[Qt.KeyboardModifiers, Qt.KeyboardModifier]
+    _ModifierType = Qt.KeyboardModifiers | Qt.KeyboardModifier
 
 
 _SPECIAL_NAMES = {
@@ -203,7 +203,7 @@ def _remap_unicode(key: Qt.Key, text: str) -> Qt.Key:
     return key
 
 
-def _check_valid_utf8(s: str, data: Union[Qt.Key, _ModifierType]) -> None:
+def _check_valid_utf8(s: str, data: Qt.Key | _ModifierType) -> None:
     """Make sure the given string is valid UTF-8.
 
     Makes sure there are no chars where Qt did fall back to weird UTF-16
@@ -259,7 +259,7 @@ class KeyParseError(Exception):
 
     """Raised by _parse_single_key/parse_keystring on parse errors."""
 
-    def __init__(self, keystr: Optional[str], error: str) -> None:
+    def __init__(self, keystr: str | None, error: str) -> None:
         if keystr is None:
             msg = "Could not parse keystring: {}".format(error)
         else:
@@ -593,7 +593,7 @@ class KeySequence:
     def __getitem__(self, item: slice) -> 'KeySequence':
         ...
 
-    def __getitem__(self, item: Union[int, slice]) -> Union[KeyInfo, 'KeySequence']:
+    def __getitem__(self, item: int | slice) -> Union[KeyInfo, 'KeySequence']:
         infos = list(self)
         if isinstance(item, slice):
             return self.__class__(*infos[item])
diff --git a/qutebrowser/keyinput/macros.py b/qutebrowser/keyinput/macros.py
index 0eb7244d6..fd495e8cf 100644
--- a/qutebrowser/keyinput/macros.py
+++ b/qutebrowser/keyinput/macros.py
@@ -33,9 +33,9 @@ class MacroRecorder:
 
     def __init__(self) -> None:
         self._macros: dict[str, list[_CommandType]] = {}
-        self._recording_macro: Optional[str] = None
+        self._recording_macro: str | None = None
         self._macro_count: dict[int, int] = {}
-        self._last_register: Optional[str] = None
+        self._last_register: str | None = None
 
     @cmdutils.register(instance='macro-recorder')
     @cmdutils.argument('win_id', value=cmdutils.Value.win_id)
diff --git a/qutebrowser/keyinput/modeman.py b/qutebrowser/keyinput/modeman.py
index 681deeff6..1979d7540 100644
--- a/qutebrowser/keyinput/modeman.py
+++ b/qutebrowser/keyinput/modeman.py
@@ -185,7 +185,7 @@ def init(win_id: int, parent: QObject) -> 'ModeManager':
     return modeman
 
 
-def instance(win_id: Union[int, str]) -> 'ModeManager':
+def instance(win_id: int | str) -> 'ModeManager':
     """Get a modemanager object.
 
     Raises UnavailableError if there is no instance available yet.
diff --git a/qutebrowser/mainwindow/mainwindow.py b/qutebrowser/mainwindow/mainwindow.py
index 6e6821612..7b43f0ea1 100644
--- a/qutebrowser/mainwindow/mainwindow.py
+++ b/qutebrowser/mainwindow/mainwindow.py
@@ -184,8 +184,8 @@ class MainWindow(QWidget):
 
     def __init__(self, *,
                  private: bool,
-                 geometry: Optional[QByteArray] = None,
-                 parent: Optional[QWidget] = None) -> None:
+                 geometry: QByteArray | None = None,
+                 parent: QWidget | None = None) -> None:
         """Create a new main window.
 
         Args:
diff --git a/qutebrowser/mainwindow/messageview.py b/qutebrowser/mainwindow/messageview.py
index 66d065360..0cec7a148 100644
--- a/qutebrowser/mainwindow/messageview.py
+++ b/qutebrowser/mainwindow/messageview.py
@@ -22,7 +22,7 @@ class Message(QLabel):
             self,
             level: usertypes.MessageLevel,
             text: str,
-            replace: Optional[str],
+            replace: str | None,
             text_format: Qt.TextFormat,
             parent: QWidget = None,
     ) -> None:
diff --git a/qutebrowser/mainwindow/prompt.py b/qutebrowser/mainwindow/prompt.py
index c8045c0e8..3fef75708 100644
--- a/qutebrowser/mainwindow/prompt.py
+++ b/qutebrowser/mainwindow/prompt.py
@@ -270,7 +270,7 @@ class PromptContainer(QWidget):
         self._layout = QVBoxLayout(self)
         self._layout.setContentsMargins(10, 10, 10, 10)
         self._win_id = win_id
-        self._prompt: Optional[_BasePrompt] = None
+        self._prompt: _BasePrompt | None = None
 
         self.setObjectName('PromptContainer')
         self.setAttribute(Qt.WidgetAttribute.WA_StyledBackground, True)
diff --git a/qutebrowser/mainwindow/statusbar/command.py b/qutebrowser/mainwindow/statusbar/command.py
index 988eed4a0..a79c527f2 100644
--- a/qutebrowser/mainwindow/statusbar/command.py
+++ b/qutebrowser/mainwindow/statusbar/command.py
@@ -238,7 +238,7 @@ class Command(misc.CommandLineEdit):
             self.clear_completion_selection.emit()
             self.hide_completion.emit()
 
-    def setText(self, text: Optional[str]) -> None:
+    def setText(self, text: str | None) -> None:
         """Extend setText to set prefix and make sure the prompt is ok."""
         if not text:
             pass
@@ -252,7 +252,7 @@ class Command(misc.CommandLineEdit):
             text = cast(str, text)
         super().setText(text)
 
-    def keyPressEvent(self, e: Optional[QKeyEvent]) -> None:
+    def keyPressEvent(self, e: QKeyEvent | None) -> None:
         """Override keyPressEvent to ignore Return key presses, and add Shift-Ins.
 
         If this widget is focused, we are in passthrough key mode, and
diff --git a/qutebrowser/mainwindow/tabbedbrowser.py b/qutebrowser/mainwindow/tabbedbrowser.py
index e0938ae36..342653485 100644
--- a/qutebrowser/mainwindow/tabbedbrowser.py
+++ b/qutebrowser/mainwindow/tabbedbrowser.py
@@ -85,7 +85,7 @@ class TabDeque:
 
         Throws IndexError on failure.
         """
-        tab: Optional[browsertab.AbstractTab] = None
+        tab: browsertab.AbstractTab | None = None
         while tab is None or tab.pending_removal or tab is cur_tab:
             tab = self._stack.pop()()
         self._stack_deleted.append(weakref.ref(cur_tab))
@@ -102,7 +102,7 @@ class TabDeque:
 
         Throws IndexError on failure.
         """
-        tab: Optional[browsertab.AbstractTab] = None
+        tab: browsertab.AbstractTab | None = None
         while tab is None or tab.pending_removal or tab is cur_tab:
             tab = self._stack_deleted.pop()()
         # On next tab-switch, current tab will be added to stack as normal.
@@ -397,7 +397,7 @@ class TabbedBrowser(QWidget):
         assert window is not None
         return window
 
-    def _tab_by_idx(self, idx: int) -> Optional[browsertab.AbstractTab]:
+    def _tab_by_idx(self, idx: int) -> browsertab.AbstractTab | None:
         """Get a browser tab by index.
 
         If no tab was found at the given index, None is returned.
diff --git a/qutebrowser/mainwindow/tabwidget.py b/qutebrowser/mainwindow/tabwidget.py
index 8d50ac45d..750bd7889 100644
--- a/qutebrowser/mainwindow/tabwidget.py
+++ b/qutebrowser/mainwindow/tabwidget.py
@@ -79,7 +79,7 @@ class TabWidget(QTabWidget):
         assert isinstance(bar, TabBar), bar
         return bar
 
-    def _tab_by_idx(self, idx: int) -> Optional[browsertab.AbstractTab]:
+    def _tab_by_idx(self, idx: int) -> browsertab.AbstractTab | None:
         """Get the tab at the given index."""
         tab = self.widget(idx)
         if tab is not None:
diff --git a/qutebrowser/misc/backendproblem.py b/qutebrowser/misc/backendproblem.py
index 9d9aef35c..1a62134fa 100644
--- a/qutebrowser/misc/backendproblem.py
+++ b/qutebrowser/misc/backendproblem.py
@@ -154,8 +154,8 @@ class _BackendImports:
 
     """Whether backend modules could be imported."""
 
-    webkit_error: Optional[str] = None
-    webengine_error: Optional[str] = None
+    webkit_error: str | None = None
+    webengine_error: str | None = None
 
 
 class _BackendProblemChecker:
diff --git a/qutebrowser/misc/crashsignal.py b/qutebrowser/misc/crashsignal.py
index 1b31536f8..03a983bd0 100644
--- a/qutebrowser/misc/crashsignal.py
+++ b/qutebrowser/misc/crashsignal.py
@@ -323,10 +323,10 @@ class SignalHandler(QObject):
         self._timer = usertypes.Timer(self, 'python_hacks')
         self._orig_handlers: MutableMapping[int, 'signal._HANDLER'] = {}
         self._activated = False
-        self._orig_wakeup_fd: Optional[int] = None
+        self._orig_wakeup_fd: int | None = None
 
         self._handlers: dict[
-            signal.Signals, Callable[[int, Optional[types.FrameType]], None]
+            signal.Signals, Callable[[int, types.FrameType | None], None]
         ] = {
             signal.SIGINT: self.interrupt,
             signal.SIGTERM: self.interrupt,
diff --git a/qutebrowser/misc/debugcachestats.py b/qutebrowser/misc/debugcachestats.py
index b12995c5c..5fafd357d 100644
--- a/qutebrowser/misc/debugcachestats.py
+++ b/qutebrowser/misc/debugcachestats.py
@@ -22,7 +22,7 @@ _CACHE_FUNCTIONS: MutableMapping[str, Any] = weakref.WeakValueDictionary()
 _T = TypeVar('_T', bound=Callable[..., Any])
 
 
-def register(name: Optional[str] = None) -> Callable[[_T], _T]:
+def register(name: str | None = None) -> Callable[[_T], _T]:
     """Register a lru_cache wrapped function for debug_cache_stats."""
     def wrapper(fn: _T) -> _T:
         fn_name = fn.__name__ if name is None else name
diff --git a/qutebrowser/misc/elf.py b/qutebrowser/misc/elf.py
index a012f4c69..9719bd676 100644
--- a/qutebrowser/misc/elf.py
+++ b/qutebrowser/misc/elf.py
@@ -289,7 +289,7 @@ def _parse_from_file(f: IO[bytes]) -> Versions:
         return _find_versions(data)
 
 
-def parse_webenginecore() -> Optional[Versions]:
+def parse_webenginecore() -> Versions | None:
     """Parse the QtWebEngineCore library file."""
     if version.is_flatpak():
         # Flatpak has Qt in /usr/lib/x86_64-linux-gnu, but QtWebEngine in /app/lib.
diff --git a/qutebrowser/misc/guiprocess.py b/qutebrowser/misc/guiprocess.py
index 2e4f33748..80d3795cd 100644
--- a/qutebrowser/misc/guiprocess.py
+++ b/qutebrowser/misc/guiprocess.py
@@ -21,7 +21,7 @@ from qutebrowser.completion.models import miscmodels
 
 
 all_processes: dict[int, Optional['GUIProcess']] = {}
-last_pid: Optional[int] = None
+last_pid: int | None = None
 
 
 @cmdutils.register()
@@ -71,8 +71,8 @@ class ProcessOutcome:
 
     what: str
     running: bool = False
-    status: Optional[QProcess.ExitStatus] = None
-    code: Optional[int] = None
+    status: QProcess.ExitStatus | None = None
+    code: int | None = None
 
     def was_successful(self) -> bool:
         """Whether the process exited successfully.
@@ -95,7 +95,7 @@ class ProcessOutcome:
             self.code == signal.SIGTERM
         )
 
-    def _crash_signal(self) -> Optional[signal.Signals]:
+    def _crash_signal(self) -> signal.Signals | None:
         """Get a Python signal (e.g. signal.SIGTERM) from a crashed process."""
         assert self.status == QProcess.ExitStatus.CrashExit
         if self.code is None:
@@ -185,10 +185,10 @@ class GUIProcess(QObject):
         self.verbose = verbose
         self._output_messages = output_messages
         self.outcome = ProcessOutcome(what=what)
-        self.cmd: Optional[str] = None
-        self.resolved_cmd: Optional[str] = None
-        self.args: Optional[Sequence[str]] = None
-        self.pid: Optional[int] = None
+        self.cmd: str | None = None
+        self.resolved_cmd: str | None = None
+        self.args: Sequence[str] | None = None
+        self.pid: int | None = None
 
         self.stdout: str = ""
         self.stderr: str = ""
diff --git a/qutebrowser/misc/ipc.py b/qutebrowser/misc/ipc.py
index eefa2e3f3..43382579a 100644
--- a/qutebrowser/misc/ipc.py
+++ b/qutebrowser/misc/ipc.py
@@ -176,7 +176,7 @@ class IPCServer(QObject):
             self._atime_timer.timeout.connect(self.update_atime)
             self._atime_timer.setTimerType(Qt.TimerType.VeryCoarseTimer)
 
-        self._server: Optional[QLocalServer] = QLocalServer(self)
+        self._server: QLocalServer | None = QLocalServer(self)
         self._server.newConnection.connect(self.handle_connection)
 
         self._socket = None
diff --git a/qutebrowser/misc/miscwidgets.py b/qutebrowser/misc/miscwidgets.py
index 7ca409afe..fe5f234ea 100644
--- a/qutebrowser/misc/miscwidgets.py
+++ b/qutebrowser/misc/miscwidgets.py
@@ -192,8 +192,8 @@ class WrapperLayout(QLayout):
 
     def __init__(self, parent=None):
         super().__init__(parent)
-        self._widget: Optional[QWidget] = None
-        self._container: Optional[QWidget] = None
+        self._widget: QWidget | None = None
+        self._container: QWidget | None = None
 
     def addItem(self, _widget):
         raise utils.Unreachable
@@ -310,10 +310,10 @@ class InspectorSplitter(QSplitter):
         self.addWidget(main_webview)
         self.setFocusProxy(main_webview)
         self.splitterMoved.connect(self._on_splitter_moved)
-        self._main_idx: Optional[int] = None
-        self._inspector_idx: Optional[int] = None
-        self._position: Optional[inspector.Position] = None
-        self._preferred_size: Optional[int] = None
+        self._main_idx: int | None = None
+        self._inspector_idx: int | None = None
+        self._position: inspector.Position | None = None
+        self._preferred_size: int | None = None
 
     def cycle_focus(self):
         """Cycle keyboard focus between the main/inspector widget."""
@@ -439,7 +439,7 @@ class InspectorSplitter(QSplitter):
         self._preferred_size = sizes[self._inspector_idx]
         self._save_preferred_size()
 
-    def resizeEvent(self, e: Optional[QResizeEvent]) -> None:
+    def resizeEvent(self, e: QResizeEvent | None) -> None:
         """Window resize event."""
         assert e is not None
         super().resizeEvent(e)
diff --git a/qutebrowser/misc/nativeeventfilter.py b/qutebrowser/misc/nativeeventfilter.py
index e93b3c6d1..5dded60ff 100644
--- a/qutebrowser/misc/nativeeventfilter.py
+++ b/qutebrowser/misc/nativeeventfilter.py
@@ -138,8 +138,8 @@ class NativeEventFilter(QAbstractNativeEventFilter):
 
     def nativeEventFilter(
         self,
-        evtype: Union[QByteArray, bytes, bytearray, memoryview],
-        message: Optional[sip.voidptr],
+        evtype: QByteArray | bytes | bytearray | memoryview,
+        message: sip.voidptr | None,
     ) -> tuple[bool, _PointerRetType]:
         """Handle XCB events."""
         # We're only installed when the platform plugin is xcb
diff --git a/qutebrowser/misc/pakjoy.py b/qutebrowser/misc/pakjoy.py
index 87b84789b..8056be8a2 100644
--- a/qutebrowser/misc/pakjoy.py
+++ b/qutebrowser/misc/pakjoy.py
@@ -124,7 +124,7 @@ class PakParser:
         except ValueError:
             raise binparsing.ParseError("Couldn't find URL in manifest")
 
-    def _maybe_get_hangouts_manifest(self, entry: PakEntry) -> Optional[bytes]:
+    def _maybe_get_hangouts_manifest(self, entry: PakEntry) -> bytes | None:
         self.fobj.seek(entry.file_offset)
         data = self.fobj.read(entry.size)
 
@@ -207,7 +207,7 @@ def _find_webengine_resources() -> pathlib.Path:
         f"Couldn't find webengine resources dir, candidates:\n{candidates_str}")
 
 
-def copy_webengine_resources() -> Optional[pathlib.Path]:
+def copy_webengine_resources() -> pathlib.Path | None:
     """Copy qtwebengine resources to local dir for patching."""
     resources_dir = _find_webengine_resources()
     work_dir = pathlib.Path(standarddir.cache()) / CACHE_DIR_NAME
@@ -262,7 +262,7 @@ def _patch(file_to_patch: pathlib.Path) -> None:
             _error(e, "Failed to apply quirk to resources pak.")
 
 
-def _error(exc: Optional[BaseException], text: str) -> None:
+def _error(exc: BaseException | None, text: str) -> None:
     if config.val.qt.workarounds.disable_hangouts_extension:
         # Explicitly requested -> hard error
         lines = ["Failed to disable Hangouts extension:", text]
diff --git a/qutebrowser/misc/sessions.py b/qutebrowser/misc/sessions.py
index b487fcd2c..6ca6db7d1 100644
--- a/qutebrowser/misc/sessions.py
+++ b/qutebrowser/misc/sessions.py
@@ -37,7 +37,7 @@ class Sentinel:
 default = Sentinel()
 session_manager = cast('SessionManager', None)
 
-ArgType = Union[str, Sentinel]
+ArgType = str | Sentinel
 
 
 def init(parent=None):
@@ -63,7 +63,7 @@ def init(parent=None):
     session_manager = SessionManager(str(base_path), parent)
 
 
-def shutdown(session: Optional[ArgType], last_window: bool) -> None:
+def shutdown(session: ArgType | None, last_window: bool) -> None:
     """Handle a shutdown by saving sessions and removing the autosave file."""
     if session_manager is None:
         return  # type: ignore[unreachable]
@@ -136,7 +136,7 @@ class SessionManager(QObject):
 
     def __init__(self, base_path, parent=None):
         super().__init__(parent)
-        self.current: Optional[str] = None
+        self.current: str | None = None
         self._base_path = base_path
         self._last_window_session = None
         self.did_load = False
@@ -436,7 +436,7 @@ class SessionManager(QObject):
                 orig_url = url
 
             if histentry.get("last_visited"):
-                last_visited: Optional[QDateTime] = QDateTime.fromString(
+                last_visited: QDateTime | None = QDateTime.fromString(
                     histentry.get("last_visited"),
                     Qt.DateFormat.ISODate,
                 )
diff --git a/qutebrowser/misc/sql.py b/qutebrowser/misc/sql.py
index e2140c242..e6e9bfb51 100644
--- a/qutebrowser/misc/sql.py
+++ b/qutebrowser/misc/sql.py
@@ -101,7 +101,7 @@ class Error(Exception):
 
     """Base class for all SQL related errors."""
 
-    def __init__(self, msg: str, error: Optional[QSqlError] = None) -> None:
+    def __init__(self, msg: str, error: QSqlError | None = None) -> None:
         super().__init__(msg)
         self.error = error
 
@@ -135,7 +135,7 @@ class BugError(Error):
 def raise_sqlite_error(msg: str, error: QSqlError) -> None:
     """Raise either a BugError or KnownError."""
     error_code = error.nativeErrorCode()
-    primary_error_code: Union[SqliteErrorCode, str]
+    primary_error_code: SqliteErrorCode | str
     try:
         # https://sqlite.org/rescode.html#pve
         primary_error_code = SqliteErrorCode(int(error_code) & 0xff)
@@ -228,8 +228,8 @@ class Database:
         return Query(self, querystr, forward_only)
 
     def table(self, name: str, fields: list[str],
-              constraints: Optional[dict[str, str]] = None,
-              parent: Optional[QObject] = None) -> 'SqlTable':
+              constraints: dict[str, str] | None = None,
+              parent: QObject | None = None) -> 'SqlTable':
         """Return a SqlTable instance linked to this Database."""
         return SqlTable(self, name, fields, constraints, parent)
 
@@ -277,9 +277,9 @@ class Transaction(contextlib.AbstractContextManager):  # type: ignore[type-arg]
             raise_sqlite_error(msg, error)
 
     def __exit__(self,
-                 _exc_type: Optional[type[BaseException]],
-                 exc_val: Optional[BaseException],
-                 _exc_tb: Optional[types.TracebackType]) -> None:
+                 _exc_type: type[BaseException] | None,
+                 exc_val: BaseException | None,
+                 _exc_tb: types.TracebackType | None) -> None:
         db = self._database.qt_database()
         if exc_val:
             log.sql.debug('Rolling back a transaction')
@@ -428,8 +428,8 @@ class SqlTable(QObject):
     database: Database
 
     def __init__(self, database: Database, name: str, fields: list[str],
-                 constraints: Optional[dict[str, str]] = None,
-                 parent: Optional[QObject] = None) -> None:
+                 constraints: dict[str, str] | None = None,
+                 parent: QObject | None = None) -> None:
         """Wrapper over a table in the SQL database.
 
         Args:
@@ -443,7 +443,7 @@ class SqlTable(QObject):
         self.database = database
         self._create_table(fields, constraints)
 
-    def _create_table(self, fields: list[str], constraints: Optional[dict[str, str]],
+    def _create_table(self, fields: list[str], constraints: dict[str, str] | None,
                       *, force: bool = False) -> None:
         """Create the table if the database is uninitialized.
 
diff --git a/qutebrowser/misc/throttle.py b/qutebrowser/misc/throttle.py
index 78bc7f29b..eb3da327e 100644
--- a/qutebrowser/misc/throttle.py
+++ b/qutebrowser/misc/throttle.py
@@ -45,8 +45,8 @@ class Throttle(QObject):
         super().__init__(parent)
         self._delay_ms = delay_ms
         self._func = func
-        self._pending_call: Optional[_CallArgs] = None
-        self._last_call_ms: Optional[int] = None
+        self._pending_call: _CallArgs | None = None
+        self._last_call_ms: int | None = None
         self._timer = usertypes.Timer(self, 'throttle-timer')
         self._timer.setSingleShot(True)
 
diff --git a/qutebrowser/misc/utilcmds.py b/qutebrowser/misc/utilcmds.py
index 548c1e54b..ca7bcfc6e 100644
--- a/qutebrowser/misc/utilcmds.py
+++ b/qutebrowser/misc/utilcmds.py
@@ -264,7 +264,7 @@ def version(win_id: int, paste: bool = False) -> None:
         pastebin_version()
 
 
-_keytester_widget: Optional[miscwidgets.KeyTesterWidget] = None
+_keytester_widget: miscwidgets.KeyTesterWidget | None = None
 
 
 @cmdutils.register(debug=True)
diff --git a/qutebrowser/qt/machinery.py b/qutebrowser/qt/machinery.py
index f39fb7d7f..d99bfd8b7 100644
--- a/qutebrowser/qt/machinery.py
+++ b/qutebrowser/qt/machinery.py
@@ -105,7 +105,7 @@ class SelectionReason(enum.Enum):
 class SelectionInfo:
     """Information about outcomes of importing Qt wrappers."""
 
-    wrapper: Optional[str] = None
+    wrapper: str | None = None
     outcomes: dict[str, str] = dataclasses.field(default_factory=dict)
     reason: SelectionReason = SelectionReason.unknown
 
@@ -164,7 +164,7 @@ def _autoselect_wrapper() -> SelectionInfo:
     return info
 
 
-def _select_wrapper(args: Optional[argparse.Namespace]) -> SelectionInfo:
+def _select_wrapper(args: argparse.Namespace | None) -> SelectionInfo:
     """Select a Qt wrapper.
 
     - If --qt-wrapper is given, use that.
diff --git a/qutebrowser/utils/debug.py b/qutebrowser/utils/debug.py
index 131639127..060af72c9 100644
--- a/qutebrowser/utils/debug.py
+++ b/qutebrowser/utils/debug.py
@@ -40,7 +40,7 @@ def log_events(klass: type[QObject]) -> type[QObject]:
     return klass
 
 
-def log_signals(obj: Union[QObject, type[QObject]]) -> Union[QObject, type[QObject]]:
+def log_signals(obj: QObject | type[QObject]) -> QObject | type[QObject]:
     """Log all signals of an object or class.
 
     Can be used as class decorator.
@@ -89,15 +89,15 @@ def log_signals(obj: Union[QObject, type[QObject]]) -> Union[QObject, type[QObje
 
 
 if machinery.IS_QT6:
-    _EnumValueType = Union[enum.Enum, int]
+    _EnumValueType = enum.Enum | int
 else:
-    _EnumValueType = Union[sip.simplewrapper, int]
+    _EnumValueType = sip.simplewrapper | int
 
 
 def _qenum_key_python(
     value: _EnumValueType,
     klass: type[_EnumValueType],
-) -> Optional[str]:
+) -> str | None:
     """New-style PyQt6: Try getting value from Python enum."""
     if isinstance(value, enum.Enum) and value.name:
         return value.name
@@ -119,7 +119,7 @@ def _qenum_key_qt(
     base: type[sip.simplewrapper],
     value: _EnumValueType,
     klass: type[_EnumValueType],
-) -> Optional[str]:
+) -> str | None:
     # On PyQt5, or PyQt6 with int passed: Try to ask Qt's introspection.
     # However, not every Qt enum value has a staticMetaObject
     try:
@@ -308,7 +308,7 @@ class log_time:  # noqa: N801,N806 pylint: disable=invalid-name
     Usable as context manager or as decorator.
     """
 
-    def __init__(self, logger: Union[logging.Logger, str],
+    def __init__(self, logger: logging.Logger | str,
                  action: str = 'operation') -> None:
         """Constructor.
 
@@ -320,16 +320,16 @@ class log_time:  # noqa: N801,N806 pylint: disable=invalid-name
             self._logger = logging.getLogger(logger)
         else:
             self._logger = logger
-        self._started: Optional[datetime.datetime] = None
+        self._started: datetime.datetime | None = None
         self._action = action
 
     def __enter__(self) -> None:
         self._started = datetime.datetime.now()
 
     def __exit__(self,
-                 _exc_type: Optional[type[BaseException]],
-                 _exc_val: Optional[BaseException],
-                 _exc_tb: Optional[types.TracebackType]) -> None:
+                 _exc_type: type[BaseException] | None,
+                 _exc_val: BaseException | None,
+                 _exc_tb: types.TracebackType | None) -> None:
         assert self._started is not None
         finished = datetime.datetime.now()
         delta = (finished - self._started).total_seconds()
diff --git a/qutebrowser/utils/docutils.py b/qutebrowser/utils/docutils.py
index c357a2cd4..d4894fea9 100644
--- a/qutebrowser/utils/docutils.py
+++ b/qutebrowser/utils/docutils.py
@@ -81,11 +81,11 @@ class DocstringParser:
             func: The function to parse the docstring for.
         """
         self._state = self.State.short
-        self._cur_arg_name: Optional[str] = None
+        self._cur_arg_name: str | None = None
         self._short_desc_parts: list[str] = []
         self._long_desc_parts: list[str] = []
         self.arg_descs: MutableMapping[
-            str, Union[str, list[str]]] = collections.OrderedDict()
+            str, str | list[str]] = collections.OrderedDict()
         doc = inspect.getdoc(func)
         handlers = {
             self.State.short: self._parse_short,
diff --git a/qutebrowser/utils/javascript.py b/qutebrowser/utils/javascript.py
index 66470155a..7a2770f11 100644
--- a/qutebrowser/utils/javascript.py
+++ b/qutebrowser/utils/javascript.py
@@ -7,8 +7,8 @@
 from typing import Union
 from collections.abc import Sequence
 
-_InnerJsArgType = Union[None, str, bool, int, float]
-_JsArgType = Union[_InnerJsArgType, Sequence[_InnerJsArgType]]
+_InnerJsArgType = None | str | bool | int | float
+_JsArgType = _InnerJsArgType | Sequence[_InnerJsArgType]
 
 
 def string_escape(text: str) -> str:
diff --git a/qutebrowser/utils/log.py b/qutebrowser/utils/log.py
index 01701b3b5..ae8d02d95 100644
--- a/qutebrowser/utils/log.py
+++ b/qutebrowser/utils/log.py
@@ -32,7 +32,7 @@ if TYPE_CHECKING:
     from qutebrowser.config import config as configmodule
 
 _log_inited = False
-_args: Optional[argparse.Namespace] = None
+_args: argparse.Namespace | None = None
 
 COLORS = ['black', 'red', 'green', 'yellow', 'blue', 'purple', 'cyan', 'white']
 COLOR_ESCAPES = {color: '\033[{}m'.format(i)
@@ -146,7 +146,7 @@ LOGGER_NAMES = [
 
 
 ram_handler: Optional['RAMHandler'] = None
-console_handler: Optional[logging.Handler] = None
+console_handler: logging.Handler | None = None
 console_filter: Optional["LogFilter"] = None
 
 
@@ -426,7 +426,7 @@ class LogFilter(logging.Filter):
         self.only_debug = only_debug
 
     @classmethod
-    def parse(cls, filter_str: Optional[str], *,
+    def parse(cls, filter_str: str | None, *,
               only_debug: bool = True) -> 'LogFilter':
         """Parse a log filter from a string."""
         if filter_str is None or filter_str == 'none':
@@ -480,7 +480,7 @@ class RAMHandler(logging.Handler):
 
     def __init__(self, capacity: int) -> None:
         super().__init__()
-        self.html_formatter: Optional[HTMLFormatter] = None
+        self.html_formatter: HTMLFormatter | None = None
         if capacity != -1:
             self._data: MutableSequence[logging.LogRecord] = collections.deque(
                 maxlen=capacity
diff --git a/qutebrowser/utils/message.py b/qutebrowser/utils/message.py
index 8fc8f6fbe..866aed8c5 100644
--- a/qutebrowser/utils/message.py
+++ b/qutebrowser/utils/message.py
@@ -25,7 +25,7 @@ class MessageInfo:
 
     level: usertypes.MessageLevel
     text: str
-    replace: Optional[str] = None
+    replace: str | None = None
     rich: bool = False
 
 
@@ -108,7 +108,7 @@ def info(message: str, *, replace: str = None, rich: bool = False) -> None:
 def _build_question(title: str,
                     text: str = None, *,
                     mode: usertypes.PromptMode,
-                    default: Union[None, bool, str] = None,
+                    default: None | bool | str = None,
                     abort_on: Iterable[pyqtBoundSignal] = (),
                     url: str = None,
                     option: bool = None) -> usertypes.Question:
diff --git a/qutebrowser/utils/objreg.py b/qutebrowser/utils/objreg.py
index c027b3cf6..e1b06d039 100644
--- a/qutebrowser/utils/objreg.py
+++ b/qutebrowser/utils/objreg.py
@@ -20,7 +20,7 @@ if TYPE_CHECKING:
     from qutebrowser.mainwindow import mainwindow
 
 
-_WindowTab = Union[str, int, None]
+_WindowTab = str | int | None
 
 
 class RegistryUnavailableError(Exception):
@@ -38,7 +38,7 @@ class CommandOnlyError(Exception):
     """Raised when an object is requested which is used for commands only."""
 
 
-_IndexType = Union[str, int]
+_IndexType = str | int
 
 
 # UserDict is only generic in Python 3.9+
@@ -153,7 +153,7 @@ def _get_tab_registry(win_id: _WindowTab,
     if tab_id is None:
         raise ValueError("Got tab_id None (win_id {})".format(win_id))
     if tab_id == 'current' and win_id is None:
-        window: Optional[QWidget] = QApplication.activeWindow()
+        window: QWidget | None = QApplication.activeWindow()
         if window is None or not hasattr(window, 'win_id'):
             raise RegistryUnavailableError('tab')
         win_id = window.win_id
@@ -179,7 +179,7 @@ def _get_window_registry(window: _WindowTab) -> ObjectRegistry:
         raise TypeError("window is None with scope window!")
     try:
         if window == 'current':
-            win: Optional[QWidget] = QApplication.activeWindow()
+            win: QWidget | None = QApplication.activeWindow()
         elif window == 'last-focused':
             win = last_focused_window()
         else:
diff --git a/qutebrowser/utils/qtlog.py b/qutebrowser/utils/qtlog.py
index 775895ed3..90fd66a89 100644
--- a/qutebrowser/utils/qtlog.py
+++ b/qutebrowser/utils/qtlog.py
@@ -16,7 +16,7 @@ from collections.abc import Iterator
 from qutebrowser.qt import core as qtcore
 from qutebrowser.utils import log
 
-_args: Optional[argparse.Namespace] = None
+_args: argparse.Namespace | None = None
 
 
 def init(args: argparse.Namespace) -> None:
@@ -43,7 +43,7 @@ def disable_qt_msghandler() -> Iterator[None]:
 
 def qt_message_handler(msg_type: qtcore.QtMsgType,
                        context: qtcore.QMessageLogContext,
-                       msg: Optional[str]) -> None:
+                       msg: str | None) -> None:
     """Qt message handler to redirect qWarning etc. to the logging system.
 
     Args:
@@ -179,7 +179,7 @@ def qt_message_handler(msg_type: qtcore.QtMsgType,
 
     assert _args is not None
     if _args.debug:
-        stack: Optional[str] = ''.join(traceback.format_stack())
+        stack: str | None = ''.join(traceback.format_stack())
     else:
         stack = None
 
diff --git a/qutebrowser/utils/qtutils.py b/qutebrowser/utils/qtutils.py
index d55f9bc2f..62f78d6db 100644
--- a/qutebrowser/utils/qtutils.py
+++ b/qutebrowser/utils/qtutils.py
@@ -62,7 +62,7 @@ class QtOSError(OSError):
         if msg is None:
             msg = dev.errorString()
 
-        self.qt_errno: Optional[QFileDevice.FileError] = None
+        self.qt_errno: QFileDevice.FileError | None = None
         if isinstance(dev, QFileDevice):
             msg = self._init_filedev(dev, msg)
 
@@ -271,7 +271,7 @@ def savefile_open(
         filename: str,
         binary: bool = False,
         encoding: str = 'utf-8'
-) -> Iterator[Union[IO[str], IO[bytes]]]:
+) -> Iterator[IO[str] | IO[bytes]]:
     """Context manager to easily use a QSaveFile."""
     f = QSaveFile(filename)
     cancelled = False
@@ -283,7 +283,7 @@ def savefile_open(
         dev = cast(BinaryIO, PyQIODevice(f))
 
         if binary:
-            new_f: Union[IO[str], IO[bytes]] = dev
+            new_f: IO[str] | IO[bytes] = dev
         else:
             new_f = io.TextIOWrapper(dev, encoding=encoding)
 
@@ -405,7 +405,7 @@ class PyQIODevice(io.BufferedIOBase):
     def readable(self) -> bool:
         return self.dev.isReadable()
 
-    def readline(self, size: Optional[int] = -1) -> bytes:
+    def readline(self, size: int | None = -1) -> bytes:
         self._check_open()
         self._check_readable()
 
@@ -416,7 +416,7 @@ class PyQIODevice(io.BufferedIOBase):
         else:
             qt_size = size + 1  # Qt also counts the NUL byte
 
-        buf: Union[QByteArray, bytes, None] = None
+        buf: QByteArray | bytes | None = None
         if self.dev.canReadLine():
             if qt_size is None:
                 buf = self.dev.readLine()
@@ -450,7 +450,7 @@ class PyQIODevice(io.BufferedIOBase):
 
     def write(  # type: ignore[override]
             self,
-            data: Union[bytes, bytearray]
+            data: bytes | bytearray
     ) -> int:
         self._check_open()
         self._check_writable()
@@ -459,11 +459,11 @@ class PyQIODevice(io.BufferedIOBase):
             raise QtOSError(self.dev)
         return num
 
-    def read(self, size: Optional[int] = None) -> bytes:
+    def read(self, size: int | None = None) -> bytes:
         self._check_open()
         self._check_readable()
 
-        buf: Union[QByteArray, bytes, None] = None
+        buf: QByteArray | bytes | None = None
         if size in [None, -1]:
             buf = self.dev.readAll()
         else:
@@ -499,8 +499,9 @@ class QtValueError(ValueError):
 if machinery.IS_QT6:
     _ProcessEventFlagType = QEventLoop.ProcessEventsFlag
 else:
-    _ProcessEventFlagType = Union[
-        QEventLoop.ProcessEventsFlag, QEventLoop.ProcessEventsFlags]
+    _ProcessEventFlagType = (
+        QEventLoop.ProcessEventsFlag
+        | QEventLoop.ProcessEventsFlags )
 
 
 class EventLoop(QEventLoop):
@@ -559,7 +560,7 @@ def interpolate_color(
         start: QColor,
         end: QColor,
         percent: int,
-        colorspace: Optional[QColor.Spec] = QColor.Spec.Rgb
+        colorspace: QColor.Spec | None = QColor.Spec.Rgb
 ) -> QColor:
     """Get an interpolated color value.
 
@@ -677,7 +678,7 @@ def library_path(which: LibraryPath) -> pathlib.Path:
     return pathlib.Path(ret)
 
 
-def extract_enum_val(val: Union[sip.simplewrapper, int, enum.Enum]) -> int:
+def extract_enum_val(val: sip.simplewrapper | int | enum.Enum) -> int:
     """Extract an int value from a Qt enum value.
 
     For Qt 5, enum values are basically Python integers.
@@ -691,7 +692,7 @@ def extract_enum_val(val: Union[sip.simplewrapper, int, enum.Enum]) -> int:
     return val
 
 
-def qobj_repr(obj: Optional[QObject]) -> str:
+def qobj_repr(obj: QObject | None) -> str:
     """Show nicer debug information for a QObject."""
     py_repr = repr(obj)
     if obj is None:
@@ -731,21 +732,21 @@ if machinery.IS_QT5:
     # Also we have a special QT_NONE, which (being Any) we can pass to functions
     # where PyQt type hints claim that it's not allowed.
 
-    def remove_optional(obj: Optional[_T]) -> _T:
+    def remove_optional(obj: _T | None) -> _T:
         return cast(_T, obj)
 
-    def add_optional(obj: _T) -> Optional[_T]:
-        return cast(Optional[_T], obj)
+    def add_optional(obj: _T) -> _T | None:
+        return cast(_T | None, obj)
 
     QT_NONE: Any = None
 else:
     # On Qt 6, all those things are handled correctly by type annotations, so we
     # have a no-op below.
 
-    def remove_optional(obj: Optional[_T]) -> Optional[_T]:
+    def remove_optional(obj: _T | None) -> _T | None:
         return obj
 
-    def add_optional(obj: Optional[_T]) -> Optional[_T]:
+    def add_optional(obj: _T | None) -> _T | None:
         return obj
 
     QT_NONE: None = None
diff --git a/qutebrowser/utils/resources.py b/qutebrowser/utils/resources.py
index 35fd62f75..be00f0b93 100644
--- a/qutebrowser/utils/resources.py
+++ b/qutebrowser/utils/resources.py
@@ -24,7 +24,7 @@ _cache: dict[str, str] = {}
 _bin_cache: dict[str, bytes] = {}
 
 
-_ResourceType = Union[Traversable, pathlib.Path]
+_ResourceType = Traversable | pathlib.Path
 
 
 def _path(filename: str) -> _ResourceType:
diff --git a/qutebrowser/utils/standarddir.py b/qutebrowser/utils/standarddir.py
index b82845a96..d80140103 100644
--- a/qutebrowser/utils/standarddir.py
+++ b/qutebrowser/utils/standarddir.py
@@ -62,7 +62,7 @@ def _unset_organization() -> Iterator[None]:
             qapp.setOrganizationName(orgname)
 
 
-def _init_config(args: Optional[argparse.Namespace]) -> None:
+def _init_config(args: argparse.Namespace | None) -> None:
     """Initialize the location for configs."""
     typ = QStandardPaths.StandardLocation.ConfigLocation
     path = _from_args(typ, args)
@@ -113,7 +113,7 @@ def config_py() -> str:
     return _locations[_Location.config_py]
 
 
-def _init_data(args: Optional[argparse.Namespace]) -> None:
+def _init_data(args: argparse.Namespace | None) -> None:
     """Initialize the location for data."""
     typ = QStandardPaths.StandardLocation.AppDataLocation
     path = _from_args(typ, args)
@@ -154,7 +154,7 @@ def data(system: bool = False) -> str:
     return _locations[_Location.data]
 
 
-def _init_cache(args: Optional[argparse.Namespace]) -> None:
+def _init_cache(args: argparse.Namespace | None) -> None:
     """Initialize the location for the cache."""
     typ = QStandardPaths.StandardLocation.CacheLocation
     path = _from_args(typ, args)
@@ -174,7 +174,7 @@ def cache() -> str:
     return _locations[_Location.cache]
 
 
-def _init_download(args: Optional[argparse.Namespace]) -> None:
+def _init_download(args: argparse.Namespace | None) -> None:
     """Initialize the location for downloads.
 
     Note this is only the default directory as found by Qt.
@@ -191,7 +191,7 @@ def download() -> str:
     return _locations[_Location.download]
 
 
-def _init_runtime(args: Optional[argparse.Namespace]) -> None:
+def _init_runtime(args: argparse.Namespace | None) -> None:
     """Initialize location for runtime data."""
     if utils.is_mac or utils.is_windows:
         # RuntimeLocation is a weird path on macOS and Windows.
@@ -277,8 +277,8 @@ def _writable_location(typ: QStandardPaths.StandardLocation) -> str:
 
 def _from_args(
         typ: QStandardPaths.StandardLocation,
-        args: Optional[argparse.Namespace]
-) -> Optional[str]:
+        args: argparse.Namespace | None
+) -> str | None:
     """Get the standard directory from an argparse namespace.
 
     Return:
@@ -337,7 +337,7 @@ def _init_dirs(args: argparse.Namespace = None) -> None:
     _init_runtime(args)
 
 
-def init(args: Optional[argparse.Namespace]) -> None:
+def init(args: argparse.Namespace | None) -> None:
     """Initialize all standard dirs."""
     if args is not None:
         # args can be None during tests
diff --git a/qutebrowser/utils/urlmatch.py b/qutebrowser/utils/urlmatch.py
index 1a558f307..72ef735cb 100644
--- a/qutebrowser/utils/urlmatch.py
+++ b/qutebrowser/utils/urlmatch.py
@@ -59,10 +59,10 @@ class UrlPattern:
         self._pattern = pattern
         self._match_all = False
         self._match_subdomains: bool = False
-        self._scheme: Optional[str] = None
-        self.host: Optional[str] = None
-        self._path: Optional[str] = None
-        self._port: Optional[int] = None
+        self._scheme: str | None = None
+        self.host: str | None = None
+        self._path: str | None = None
+        self._port: int | None = None
 
         # > The special pattern <all_urls> matches any URL that starts with a
         # > permitted scheme.
@@ -92,10 +92,10 @@ class UrlPattern:
     def _to_tuple(self) -> tuple[
         bool,  # _match_all
         bool,  # _match_subdomains
-        Optional[str],  # _scheme
-        Optional[str],  # host
-        Optional[str],  # _path
-        Optional[int],  # _port
+        str | None,  # _scheme
+        str | None,  # host
+        str | None,  # _path
+        int | None,  # _port
     ]:
         """Get a pattern with information used for __eq__/__hash__."""
         return (self._match_all, self._match_subdomains, self._scheme,
diff --git a/qutebrowser/utils/urlutils.py b/qutebrowser/utils/urlutils.py
index 839fdbe84..81301c68c 100644
--- a/qutebrowser/utils/urlutils.py
+++ b/qutebrowser/utils/urlutils.py
@@ -29,7 +29,7 @@ from qutebrowser.browser.network import pac
 
 
 if machinery.IS_QT6:
-    UrlFlagsType = Union[QUrl.UrlFormattingOption, QUrl.ComponentFormattingOption]
+    UrlFlagsType = QUrl.UrlFormattingOption | QUrl.ComponentFormattingOption
 
     class FormatOption:
         """Simple wrapper around Qt enums to fix typing problems on Qt 5."""
@@ -42,12 +42,12 @@ if machinery.IS_QT6:
         REMOVE_PASSWORD = QUrl.UrlFormattingOption.RemovePassword
         REMOVE_QUERY = QUrl.UrlFormattingOption.RemoveQuery
 else:
-    UrlFlagsType = Union[
-        QUrl.FormattingOptions,
-        QUrl.UrlFormattingOption,
-        QUrl.ComponentFormattingOption,
-        QUrl.ComponentFormattingOptions,
-    ]
+    UrlFlagsType = (
+        QUrl.FormattingOptions
+        | QUrl.UrlFormattingOption
+        | QUrl.ComponentFormattingOption
+        | QUrl.ComponentFormattingOptions
+    )
 
     class _QtFormattingOptions(QUrl.FormattingOptions):
         """WORKAROUND for invalid stubs.
@@ -112,7 +112,7 @@ class InvalidUrlError(Error):
         super().__init__(self.msg)
 
 
-def _parse_search_term(s: str) -> tuple[Optional[str], Optional[str]]:
+def _parse_search_term(s: str) -> tuple[str | None, str | None]:
     """Get a search engine name and search term from a string.
 
     Args:
@@ -128,8 +128,8 @@ def _parse_search_term(s: str) -> tuple[Optional[str], Optional[str]]:
 
     if len(split) == 2:
         if split[0] in config.val.url.searchengines:
-            engine: Optional[str] = split[0]
-            term: Optional[str] = split[1]
+            engine: str | None = split[0]
+            term: str | None = split[1]
         else:
             engine = None
             term = s
@@ -390,7 +390,7 @@ def raise_cmdexc_if_invalid(url: QUrl) -> None:
 def get_path_if_valid(pathstr: str,
                       cwd: str = None,
                       relative: bool = False,
-                      check_exists: bool = False) -> Optional[str]:
+                      check_exists: bool = False) -> str | None:
     """Check if path is a valid path.
 
     Args:
@@ -408,7 +408,7 @@ def get_path_if_valid(pathstr: str,
     expanded = os.path.expanduser(pathstr)
 
     if os.path.isabs(expanded):
-        path: Optional[str] = expanded
+        path: str | None = expanded
     elif relative and cwd:
         path = os.path.join(cwd, expanded)
     elif relative:
@@ -435,7 +435,7 @@ def get_path_if_valid(pathstr: str,
     return path
 
 
-def filename_from_url(url: QUrl, fallback: str = None) -> Optional[str]:
+def filename_from_url(url: QUrl, fallback: str = None) -> str | None:
     """Get a suitable filename from a URL.
 
     Args:
@@ -616,7 +616,7 @@ class InvalidProxyTypeError(Exception):
         super().__init__("Invalid proxy type {}!".format(typ))
 
 
-def proxy_from_url(url: QUrl) -> Union[QNetworkProxy, pac.PACFetcher]:
+def proxy_from_url(url: QUrl) -> QNetworkProxy | pac.PACFetcher:
     """Create a QNetworkProxy from QUrl and a proxy type.
 
     Args:
diff --git a/qutebrowser/utils/usertypes.py b/qutebrowser/utils/usertypes.py
index c8e92bf17..418b03135 100644
--- a/qutebrowser/utils/usertypes.py
+++ b/qutebrowser/utils/usertypes.py
@@ -57,7 +57,7 @@ class NeighborList(Sequence[_T]):
         exception = enum.auto()
 
     def __init__(self, items: Sequence[_T] = None,
-                 default: Union[_T, Unset] = UNSET,
+                 default: _T | Unset = UNSET,
                  mode: Modes = Modes.exception) -> None:
         """Constructor.
 
@@ -78,12 +78,12 @@ class NeighborList(Sequence[_T]):
 
         if not isinstance(default, Unset):
             idx = self._items.index(default)
-            self._idx: Optional[int] = idx
+            self._idx: int | None = idx
         else:
             self._idx = None
 
         self._mode = mode
-        self.fuzzyval: Optional[int] = None
+        self.fuzzyval: int | None = None
 
     def __getitem__(self, key: int) -> _T:  # type: ignore[override]
         return self._items[key]
@@ -393,13 +393,13 @@ class Question(QObject):
 
     def __init__(self, parent: QObject = None) -> None:
         super().__init__(parent)
-        self.mode: Optional[PromptMode] = None
-        self.default: Union[bool, str, None] = None
-        self.title: Optional[str] = None
-        self.text: Optional[str] = None
-        self.url: Optional[str] = None
-        self.option: Optional[bool] = None
-        self.answer: Union[str, bool, None] = None
+        self.mode: PromptMode | None = None
+        self.default: bool | str | None = None
+        self.title: str | None = None
+        self.text: str | None = None
+        self.url: str | None = None
+        self.option: bool | None = None
+        self.answer: str | bool | None = None
         self.is_aborted = False
         self.interrupted = False
 
@@ -446,7 +446,7 @@ class Timer(QTimer):
 
     def __init__(self, parent: QObject = None, name: str = None) -> None:
         super().__init__(parent)
-        self._start_time: Optional[float] = None
+        self._start_time: float | None = None
         self.timeout.connect(self._validity_check_handler)
         if name is None:
             self._name = "unnamed"
@@ -515,7 +515,7 @@ class AbstractCertificateErrorWrapper:
     """A wrapper over an SSL/certificate error."""
 
     def __init__(self) -> None:
-        self._certificate_accepted: Optional[bool] = None
+        self._certificate_accepted: bool | None = None
 
     def __str__(self) -> str:
         raise NotImplementedError
diff --git a/qutebrowser/utils/utils.py b/qutebrowser/utils/utils.py
index 37a72c07b..577674274 100644
--- a/qutebrowser/utils/utils.py
+++ b/qutebrowser/utils/utils.py
@@ -40,7 +40,7 @@ except ImportError:  # pragma: no cover
 
 from qutebrowser.utils import log
 
-fake_clipboard: Optional[str] = None
+fake_clipboard: str | None = None
 log_clipboard = False
 
 is_mac = sys.platform.startswith('darwin')
@@ -231,7 +231,7 @@ def format_seconds(total_seconds: int) -> str:
     return prefix + ':'.join(chunks)
 
 
-def format_size(size: Optional[float], base: int = 1024, suffix: str = '') -> str:
+def format_size(size: float | None, base: int = 1024, suffix: str = '') -> str:
     """Format a byte size so it's human readable.
 
     Inspired by https://stackoverflow.com/q/1094841
@@ -408,7 +408,7 @@ def qualname(obj: Any) -> str:
         return repr(obj)
 
 
-_ExceptionType = Union[type[BaseException], tuple[type[BaseException]]]
+_ExceptionType = type[BaseException] | tuple[type[BaseException]]
 
 
 def raises(exc: _ExceptionType, func: Callable[..., Any], *args: Any) -> bool:
@@ -439,7 +439,7 @@ def force_encoding(text: str, encoding: str) -> str:
 
 
 def sanitize_filename(name: str,
-                      replacement: Optional[str] = '_',
+                      replacement: str | None = '_',
                       shorten: bool = False) -> str:
     """Replace invalid filename characters.
 
@@ -647,7 +647,7 @@ def expand_windows_drive(path: str) -> str:
         return path
 
 
-def yaml_load(f: Union[str, IO[str]]) -> Any:
+def yaml_load(f: str | IO[str]) -> Any:
     """Wrapper over yaml.load using the C loader if possible."""
     start = datetime.datetime.now()
 
@@ -687,7 +687,7 @@ def yaml_load(f: Union[str, IO[str]]) -> Any:
     return data
 
 
-def yaml_dump(data: Any, f: IO[str] = None) -> Optional[str]:
+def yaml_dump(data: Any, f: IO[str] = None) -> str | None:
     """Wrapper over yaml.dump using the C dumper if possible.
 
     Also returns a str instead of bytes.
@@ -777,7 +777,7 @@ def parse_duration(duration: str) -> int:
     return milliseconds
 
 
-def mimetype_extension(mimetype: str) -> Optional[str]:
+def mimetype_extension(mimetype: str) -> str | None:
     """Get a suitable extension for a given mimetype.
 
     This mostly delegates to Python's mimetypes.guess_extension(), but backports some
@@ -876,7 +876,7 @@ def parse_point(s: str) -> QPoint:
         raise ValueError(e)
 
 
-def match_globs(patterns: list[str], value: str) -> Optional[str]:
+def match_globs(patterns: list[str], value: str) -> str | None:
     """Match a list of glob-like patterns against a value.
 
     Return:
diff --git a/qutebrowser/utils/version.py b/qutebrowser/utils/version.py
index 9189be381..a47f3f214 100644
--- a/qutebrowser/utils/version.py
+++ b/qutebrowser/utils/version.py
@@ -74,12 +74,12 @@ class DistributionInfo:
 
     """Information about the running distribution."""
 
-    id: Optional[str]
+    id: str | None
     parsed: 'Distribution'
     pretty: str
 
 
-pastebin_url: Optional[str] = None
+pastebin_url: str | None = None
 
 
 class Distribution(enum.Enum):
@@ -106,7 +106,7 @@ class Distribution(enum.Enum):
     solus = enum.auto()
 
 
-def _parse_os_release() -> Optional[dict[str, str]]:
+def _parse_os_release() -> dict[str, str] | None:
     """Parse an /etc/os-release file."""
     filename = os.environ.get('QUTE_FAKE_OS_RELEASE', '/etc/os-release')
     info = {}
@@ -124,7 +124,7 @@ def _parse_os_release() -> Optional[dict[str, str]]:
     return info
 
 
-def distribution() -> Optional[DistributionInfo]:
+def distribution() -> DistributionInfo | None:
     """Get some information about the running Linux distribution.
 
     Returns:
@@ -178,7 +178,7 @@ def is_flatpak() -> bool:
 _FLATPAK_INFO_PATH = '/.flatpak-info'
 
 
-def flatpak_id() -> Optional[str]:
+def flatpak_id() -> str | None:
     """Get the ID of the currently running Flatpak (or None if outside of Flatpak)."""
     if 'FLATPAK_ID' in os.environ:
         return os.environ['FLATPAK_ID']
@@ -195,7 +195,7 @@ def flatpak_id() -> Optional[str]:
     return parser['Application']['name']
 
 
-def _git_str() -> Optional[str]:
+def _git_str() -> str | None:
     """Try to find out git version.
 
     Return:
@@ -229,7 +229,7 @@ def _call_git(gitpath: str, *args: str) -> str:
         stdout=subprocess.PIPE).stdout.decode('UTF-8').strip()
 
 
-def _git_str_subprocess(gitpath: str) -> Optional[str]:
+def _git_str_subprocess(gitpath: str) -> str | None:
     """Try to get the git commit ID and timestamp by calling git.
 
     Args:
@@ -296,13 +296,13 @@ class ModuleInfo:
         self,
         name: str,
         version_attributes: Sequence[str],
-        min_version: Optional[str] = None
+        min_version: str | None = None
     ):
         self.name = name
         self._version_attributes = version_attributes
         self.min_version = min_version
         self._installed = False
-        self._version: Optional[str] = None
+        self._version: str | None = None
         self._initialized = False
 
     def _reset_cache(self) -> None:
@@ -341,7 +341,7 @@ class ModuleInfo:
 
         self._initialized = True
 
-    def get_version(self) -> Optional[str]:
+    def get_version(self) -> str | None:
         """Finds the module version if it exists."""
         if not self._initialized:
             self._initialize_info()
@@ -353,7 +353,7 @@ class ModuleInfo:
             self._initialize_info()
         return self._installed
 
-    def is_outdated(self) -> Optional[bool]:
+    def is_outdated(self) -> bool | None:
         """Checks whether the module is outdated.
 
         Return:
@@ -505,7 +505,7 @@ def _pdfjs_version() -> str:
         return '{} ({})'.format(pdfjs_version, file_path)
 
 
-def _get_pyqt_webengine_qt_version() -> Optional[str]:
+def _get_pyqt_webengine_qt_version() -> str | None:
     """Get the version of the PyQtWebEngine-Qt package.
 
     With PyQtWebEngine 5.15.3, the QtWebEngine binary got split into its own
@@ -541,10 +541,10 @@ class WebEngineVersions:
     """Version numbers for QtWebEngine and the underlying Chromium."""
 
     webengine: utils.VersionNumber
-    chromium: Optional[str]
+    chromium: str | None
     source: str
-    chromium_security: Optional[str] = None
-    chromium_major: Optional[int] = dataclasses.field(init=False)
+    chromium_security: str | None = None
+    chromium_major: int | None = dataclasses.field(init=False)
 
     # Dates based on https://chromium.googlesource.com/chromium/src/+refs
     _BASES: ClassVar[dict[int, str]] = {
@@ -563,7 +563,7 @@ class WebEngineVersions:
     }
 
     # Dates based on https://chromereleases.googleblog.com/
-    _CHROMIUM_VERSIONS: ClassVar[dict[utils.VersionNumber, tuple[str, Optional[str]]]] = {
+    _CHROMIUM_VERSIONS: ClassVar[dict[utils.VersionNumber, tuple[str, str | None]]] = {
         # ====== UNSUPPORTED =====
 
         # Qt 5.12: Chromium 69
@@ -732,7 +732,7 @@ class WebEngineVersions:
     def _infer_chromium_version(
             cls,
             pyqt_webengine_version: utils.VersionNumber,
-    ) -> tuple[Optional[str], Optional[str]]:
+    ) -> tuple[str | None, str | None]:
         """Infer the Chromium version based on the PyQtWebEngine version.
 
         Returns:
@@ -760,8 +760,8 @@ class WebEngineVersions:
     def from_api(
         cls,
         qtwe_version: str,
-        chromium_version: Optional[str],
-        chromium_security: Optional[str] = None,
+        chromium_version: str | None,
+        chromium_security: str | None = None,
     ) -> 'WebEngineVersions':
         """Get the versions based on the exact versions.
 
@@ -1036,16 +1036,16 @@ class OpenGLInfo:
     # The name of the vendor. Examples:
     # - nouveau
     # - "Intel Open Source Technology Center", "Intel", "Intel Inc."
-    vendor: Optional[str] = None
+    vendor: str | None = None
 
     # The OpenGL version as a string. See tests for examples.
-    version_str: Optional[str] = None
+    version_str: str | None = None
 
     # The parsed version as a (major, minor) tuple of ints
-    version: Optional[tuple[int, ...]] = None
+    version: tuple[int, ...] | None = None
 
     # The vendor specific information following the version number
-    vendor_specific: Optional[str] = None
+    vendor_specific: str | None = None
 
     def __str__(self) -> str:
         if self.gles:
@@ -1083,7 +1083,7 @@ class OpenGLInfo:
 
 
 @functools.lru_cache(maxsize=1)
-def opengl_info() -> Optional[OpenGLInfo]:  # pragma: no cover
+def opengl_info() -> OpenGLInfo | None:  # pragma: no cover
     """Get the OpenGL vendor used.
 
     This returns a string such as 'nouveau' or
@@ -1098,7 +1098,7 @@ def opengl_info() -> Optional[OpenGLInfo]:  # pragma: no cover
         vendor, version = override.split(', ', maxsplit=1)
         return OpenGLInfo.parse(vendor=vendor, version=version)
 
-    old_context: Optional[QOpenGLContext] = QOpenGLContext.currentContext()
+    old_context: QOpenGLContext | None = QOpenGLContext.currentContext()
     old_surface = None if old_context is None else old_context.surface()
 
     surface = QOffscreenSurface()
diff --git a/run_profile.py.lprof b/run_profile.py.lprof
new file mode 100644
index 000000000..c02063883
Binary files /dev/null and b/run_profile.py.lprof differ
diff --git a/tests/end2end/data/brave-adblock/generate.py b/tests/end2end/data/brave-adblock/generate.py
index 1dae5b6e5..cb32b7178 100644
--- a/tests/end2end/data/brave-adblock/generate.py
+++ b/tests/end2end/data/brave-adblock/generate.py
@@ -18,7 +18,7 @@ CACHE_PATH = pathlib.Path(tempfile.gettempdir(), "ublock-matches-cache.tsv")
 ROWS_TO_USE = 30_000
 
 
-def type_rename(type_str: str) -> Optional[str]:
+def type_rename(type_str: str) -> str | None:
     """Use the same resource type names as QtWebEngine."""
     if type_str == "other":
         return "unknown"
diff --git a/tests/end2end/test_hints_html.py b/tests/end2end/test_hints_html.py
index bd787bc4a..532b91fad 100644
--- a/tests/end2end/test_hints_html.py
+++ b/tests/end2end/test_hints_html.py
@@ -25,8 +25,8 @@ def collect_tests():
 @dataclasses.dataclass
 class ParsedFile:
 
-    target: Optional[str]
-    qtwebengine_todo: Optional[str]
+    target: str | None
+    qtwebengine_todo: str | None
 
 
 class InvalidFile(Exception):
diff --git a/tests/helpers/testutils.py b/tests/helpers/testutils.py
index 9b13b9dfe..abf81b966 100644
--- a/tests/helpers/testutils.py
+++ b/tests/helpers/testutils.py
@@ -375,7 +375,7 @@ def enum_members(base, enumtype):
         }
 
 
-def is_userns_restricted() -> Optional[bool]:
+def is_userns_restricted() -> bool | None:
     if not utils.is_linux:
         return None
 
diff --git a/tests/unit/browser/test_notification.py b/tests/unit/browser/test_notification.py
index 6c888f084..b7d98eb91 100644
--- a/tests/unit/browser/test_notification.py
+++ b/tests/unit/browser/test_notification.py
@@ -29,7 +29,7 @@ class FakeDBusMessage:
         signature: str,
         *arguments: Any,
         typ: QDBusMessage.MessageType = QDBusMessage.MessageType.ReplyMessage,
-        error_name: Optional[str] = None,
+        error_name: str | None = None,
     ) -> None:
         self._signature = signature
         self._arguments = arguments
@@ -170,7 +170,7 @@ class FakeNotificationAdapter(notification.AbstractNotificationAdapter):
     def present(
         self,
         qt_notification: "QWebEngineNotification", *,
-        replaces_id: Optional[int],
+        replaces_id: int | None,
     ) -> int:
         self.presented.append(qt_notification)
         return next(self.id_gen)
diff --git a/tests/unit/keyinput/key_data.py b/tests/unit/keyinput/key_data.py
index 5b05252f2..f8cbd19eb 100644
--- a/tests/unit/keyinput/key_data.py
+++ b/tests/unit/keyinput/key_data.py
@@ -28,10 +28,10 @@ class Key:
     """
 
     attribute: str
-    name: Optional[str] = None
+    name: str | None = None
     text: str = ''
     uppertext: str = ''
-    member: Optional[int] = None
+    member: int | None = None
     qtest: bool = True
 
     def __post_init__(self):
@@ -54,8 +54,8 @@ class Modifier:
     """
 
     attribute: str
-    name: Optional[str] = None
-    member: Optional[int] = None
+    name: str | None = None
+    member: int | None = None
 
     def __post_init__(self):
         self.member = getattr(Qt.KeyboardModifier, self.attribute + 'Modifier')
diff --git a/tests/unit/misc/test_ipc.py b/tests/unit/misc/test_ipc.py
index f611428af..fd7472790 100644
--- a/tests/unit/misc/test_ipc.py
+++ b/tests/unit/misc/test_ipc.py
@@ -632,7 +632,7 @@ class TestSendOrListen:
         no_err_windows: bool
         basedir: str
         command: list[str]
-        target: Optional[str]
+        target: str | None
 
     @pytest.fixture
     def args(self):
diff --git a/tests/unit/test_qt_machinery.py b/tests/unit/test_qt_machinery.py
index 677494ee5..ea193767c 100644
--- a/tests/unit/test_qt_machinery.py
+++ b/tests/unit/test_qt_machinery.py
@@ -210,7 +210,7 @@ def modules():
 )
 def test_autoselect(
     stubs: Any,
-    available: dict[str, Union[bool, Exception]],
+    available: dict[str, bool | Exception],
     expected: machinery.SelectionInfo,
     monkeypatch: pytest.MonkeyPatch,
 ):
@@ -222,9 +222,9 @@ def test_autoselect(
 class SelectWrapperCase:
     name: str
     expected: machinery.SelectionInfo
-    args: Optional[argparse.Namespace] = None
-    env: Optional[str] = None
-    override: Optional[str] = None
+    args: argparse.Namespace | None = None
+    env: str | None = None
+    override: str | None = None
 
     def __str__(self):
         return self.name
@@ -345,8 +345,8 @@ class TestSelectWrapper:
     )
     def test_autoselect_by_default(
         self,
-        args: Optional[argparse.Namespace],
-        env: Optional[str],
+        args: argparse.Namespace | None,
+        env: str | None,
         monkeypatch: pytest.MonkeyPatch,
     ):
         """Test that the default behavior is to autoselect a wrapper.