diff --git a/src/http/helpers/prefixes.ts b/src/http/helpers/prefixes.ts
new file mode 100644
index 0000000..305b3cf
--- /dev/null
+++ b/src/http/helpers/prefixes.ts
@@ -0,0 +1,55 @@
+interface MatchPrefixesParams {
+	// One prefix
+	prefix?: string;
+
+	// Comma separated prefixes
+	prefixes?: string;
+}
+
+/**
+ * Filter prefixes
+ *
+ * returnEmpty = true -> if no filter params set, returns empty array
+ * returnEmpty = false -> if no filter params set, returns all filters
+ */
+export function filterPrefixes(prefixes: string[], params: MatchPrefixesParams, returnEmpty: boolean): string[] {
+	const exactMatch = params.prefix;
+	if (exactMatch) {
+		// Exact match
+		return prefixes.indexOf(exactMatch) === -1 ? [] : [exactMatch];
+	}
+
+	const partialMatch = params.prefixes;
+	if (partialMatch) {
+		// Split matches by partial and full
+		const exact: Set<string> = new Set();
+		const partial: string[] = [];
+
+		partialMatch.split(',').forEach((prefix) => {
+			if (prefix.slice(-1) === '-') {
+				// Partial prefix: 'mdi-'
+				partial.push(prefix);
+			} else {
+				// Exact match
+				exact.add(prefix);
+			}
+		});
+
+		// Filter prefixes
+		return prefixes.filter((prefix) => {
+			if (exact.has(prefix)) {
+				return true;
+			}
+			for (let i = 0; i < partial.length; i++) {
+				const match = partial[i];
+				if (prefix.slice(0, match.length) === match) {
+					return true;
+				}
+			}
+			return false;
+		});
+	}
+
+	// No filters
+	return returnEmpty ? [] : prefixes;
+}
diff --git a/src/http/index.ts b/src/http/index.ts
index 67c2c6d..981bec0 100644
--- a/src/http/index.ts
+++ b/src/http/index.ts
@@ -3,6 +3,7 @@ import { appConfig } from '../config/app';
 import { runWhenLoaded } from '../data/loading';
 import { iconNameRoutePartialRegEx, iconNameRouteRegEx, splitIconName } from '../misc/name';
 import { generateIconsDataResponse } from './responses/icons';
+import { generateLastModifiedResponse } from './responses/modified';
 import { generateSVGResponse } from './responses/svg';
 import { initVersionResponse, versionResponse } from './responses/version';
 
@@ -97,6 +98,13 @@ export async function startHTTPServer() {
 		});
 	});
 
+	// Last modification time
+	server.get('/last-modified', (req, res) => {
+		runWhenLoaded(() => {
+			generateLastModifiedResponse(req.query, res);
+		});
+	});
+
 	// Options
 	server.options('/*', (req, res) => {
 		res.send(200);
diff --git a/src/http/responses/modified.ts b/src/http/responses/modified.ts
new file mode 100644
index 0000000..fef7fff
--- /dev/null
+++ b/src/http/responses/modified.ts
@@ -0,0 +1,47 @@
+import type { FastifyReply, FastifyRequest } from 'fastify';
+import { getPrefixes, iconSets } from '../../data/icon-sets';
+import type { LastModifiedAPIResponse } from '../../types/server/modified';
+import { checkJSONPQuery, sendJSONResponse } from '../helpers/json';
+import { filterPrefixes } from '../helpers/prefixes';
+
+/**
+ * Generate icons data
+ */
+export function generateLastModifiedResponse(query: FastifyRequest['query'], res: FastifyReply) {
+	const q = (query || {}) as Record<string, string>;
+	const wrap = checkJSONPQuery(q);
+	if (!wrap) {
+		// Invalid JSONP callback
+		res.send(400);
+		return;
+	}
+
+	// Filter prefixes
+	const prefixes = filterPrefixes(getPrefixes(), q, false);
+
+	// Generate result
+	const lastModified = Object.create(null) as Record<string, number>;
+	const response: LastModifiedAPIResponse = {
+		lastModified,
+	};
+	let found = false;
+
+	for (let i = 0; i < prefixes.length; i++) {
+		const prefix = prefixes[i];
+		const item = iconSets[prefix];
+		if (item) {
+			const value = item.item.common.lastModified;
+			if (value) {
+				found = true;
+				lastModified[prefix] = value;
+			}
+		}
+	}
+
+	if (!found) {
+		// No matches
+		res.send(404);
+		return;
+	}
+	sendJSONResponse(response, q, wrap, res);
+}
diff --git a/src/types/server/modified.ts b/src/types/server/modified.ts
new file mode 100644
index 0000000..1a7333e
--- /dev/null
+++ b/src/types/server/modified.ts
@@ -0,0 +1,8 @@
+/**
+ * Response for `/last-modified` query
+ *
+ * Key is prefix, value is last modification time number
+ */
+export interface LastModifiedAPIResponse {
+	lastModified: Record<string, number>;
+}