diff --git a/apps/dm/src/lib/server.ts b/apps/dm/src/lib/server.ts
index e543958..3a8140b 100644
--- a/apps/dm/src/lib/server.ts
+++ b/apps/dm/src/lib/server.ts
@@ -30,6 +30,8 @@ export interface UpdateInfo {
   latest?: string;
   /** Release notes of the newest release. */
   url?: string;
+  /** Whether the server asks GitHub for new releases, so it can check now. */
+  canCheck?: boolean;
 }
 
 /** The server's version and whether a newer release is out. */
@@ -55,6 +57,22 @@ export interface UpdaterInfo {
 /** Set when the server has an updater container, which enables the update button. */
 export const updaterInfo = ref<UpdaterInfo>();
 
+/** Asks the server to look for a new release now; undefined if it could not ask. */
+export async function checkForUpdates(): Promise<'newer' | 'current' | 'unreachable' | undefined> {
+  try {
+    const response = await fetch('/api/updates/check', { method: 'POST' });
+    if (!response.ok) return undefined;
+    const data = (await response.json()) as {
+      result: 'newer' | 'current' | 'unreachable';
+      update: UpdateInfo;
+    };
+    updateInfo.value = data.update;
+    return data.result;
+  } catch {
+    return undefined;
+  }
+}
+
 /** Asks the server to update itself; false if the updater could not start. */
 export async function startUpdate(): Promise<boolean> {
   try {
diff --git a/apps/dm/src/locales/de.json b/apps/dm/src/locales/de.json
index a6b1e18..e4a8eee 100644
--- a/apps/dm/src/locales/de.json
+++ b/apps/dm/src/locales/de.json
@@ -18,6 +18,11 @@
     "devVersion": "Lorewarden, aus dem Quellcode gebaut. Aktualisieren mit git pull.",
     "updateAvailable": "Version {version} ist verfügbar.",
     "releaseNotes": "Was ist neu",
+    "checkForUpdates": "Nach Updates suchen",
+    "checkResult": {
+      "current": "Lorewarden ist auf dem neuesten Stand.",
+      "unreachable": "GitHub war nicht erreichbar. Versuch es später noch einmal."
+    },
     "howToUpdate": "Wenn du Lorewarden mit Docker Compose betreibst, aktualisierst du es auf dem Server so:",
     "howToUpdateSource": "Wenn du es aus dem Quellcode startest, nimm git pull und pnpm start. Deine Abenteuer bleiben erhalten.",
     "combat": "Kampf",
diff --git a/apps/dm/src/locales/en.json b/apps/dm/src/locales/en.json
index 0e99cdb..dec58d8 100644
--- a/apps/dm/src/locales/en.json
+++ b/apps/dm/src/locales/en.json
@@ -18,6 +18,11 @@
     "devVersion": "Lorewarden, built from source. Update with git pull.",
     "updateAvailable": "Version {version} is available.",
     "releaseNotes": "What's new",
+    "checkForUpdates": "Check for updates",
+    "checkResult": {
+      "current": "Lorewarden is up to date.",
+      "unreachable": "GitHub could not be reached. Try again later."
+    },
     "howToUpdate": "If you run Lorewarden with Docker Compose, update it on the server with:",
     "howToUpdateSource": "If you run it from source, use git pull and pnpm start. Your adventures are kept.",
     "combat": "Combat",
diff --git a/apps/dm/src/views/SettingsView.vue b/apps/dm/src/views/SettingsView.vue
index 6f24771..bc97a5c 100644
--- a/apps/dm/src/views/SettingsView.vue
+++ b/apps/dm/src/views/SettingsView.vue
@@ -15,6 +15,7 @@ import {
 } from '../lib/auth';
 import { languageOptions } from '../lib/languages';
 import {
+  checkForUpdates,
   dataDir,
   setAutoUpdate,
   startUpdate,
@@ -85,6 +86,18 @@ async function savePassword() {
   repeatedPassword.value = '';
 }
 
+const checking = ref(false);
+/** What the last "Check for updates" found, unless it found a new release. */
+const checkResult = ref<'current' | 'unreachable'>();
+
+async function checkNow() {
+  checking.value = true;
+  checkResult.value = undefined;
+  const result = await checkForUpdates();
+  checking.value = false;
+  if (result !== 'newer') checkResult.value = result ?? 'unreachable';
+}
+
 const updateRefused = ref(false);
 const updating = computed(() => updaterInfo.value?.status?.state === 'running');
 
@@ -252,6 +265,17 @@ function onLocale(event: Event) {
             : t('settings.currentVersion', { version: updateInfo.current })
         }}
       </p>
+      <template v-if="updateInfo.canCheck && !updateInfo.latest">
+        <div class="row">
+          <button type="button" :disabled="checking" @click="checkNow">
+            <RefreshCw :size="16" aria-hidden="true" />
+            {{ t('settings.checkForUpdates') }}
+          </button>
+        </div>
+        <p v-if="checkResult" class="hint" role="status">
+          {{ t(`settings.checkResult.${checkResult}`) }}
+        </p>
+      </template>
       <template v-if="updateInfo.latest">
         <p>
           <strong>{{ t('settings.updateAvailable', { version: updateInfo.latest }) }}</strong>{{ ' ' }}
diff --git a/docs/self-hosting.md b/docs/self-hosting.md
index 442b54d..a909cda 100644
--- a/docs/self-hosting.md
+++ b/docs/self-hosting.md
@@ -153,7 +153,7 @@ Pass both with `--server https://lorewarden.example.org --token ...`. Keep the t
 
 ## Updates
 
-The server asks GitHub when it starts and then every 12 hours whether a newer release is out. If so, the settings icon in the game master app gets a dot and the settings page shows the new version with a link to its release notes. To update by hand, run on the server:
+The server asks GitHub when it starts and then every 12 hours whether a newer release is out. If so, the settings icon in the game master app gets a dot and the settings page shows the new version with a link to its release notes. To look right away, for example just after a release, press **Check for updates** there. To update by hand, run on the server:
 
 ```sh
 docker compose pull && docker compose up -d
diff --git a/packages/server/src/main.ts b/packages/server/src/main.ts
index dc4579e..c89805a 100644
--- a/packages/server/src/main.ts
+++ b/packages/server/src/main.ts
@@ -9,7 +9,7 @@ import { OAuth } from './oauth';
 import { DEFAULT_SERVER_PORT, LorewardenServer } from './server';
 import { Store } from './store';
 import { Updater } from './updater';
-import { watchForUpdates } from './updates';
+import { type UpdateWatcher, watchForUpdates } from './updates';
 
 const DEFAULT_UPDATER_URL = 'http://updater:47617';
 
@@ -119,6 +119,7 @@ const updater = updaterToken
 const apiHost =
   host === '0.0.0.0' || host === '::' ? '127.0.0.1' : host.includes(':') ? `[${host}]` : host;
 
+let updates: UpdateWatcher | undefined;
 const server = new LorewardenServer({
   store: new Store(dir),
   auth,
@@ -131,6 +132,9 @@ const server = new LorewardenServer({
   allowedOrigins: values.origin,
   version: __LOREWARDEN_VERSION__,
   updater,
+  checkForUpdates: checkForUpdates
+    ? () => updates?.check() ?? Promise.resolve('unreachable')
+    : undefined,
 });
 try {
   const listening = await server.listen(port, host);
@@ -143,7 +147,9 @@ try {
       : 'No local network found. Players need to be in the same Wi-Fi as this computer.',
   );
   console.log(`Version ${__LOREWARDEN_VERSION__}. Press Ctrl+C to stop.`);
-  if (checkForUpdates) watchForUpdates(__LOREWARDEN_VERSION__, (info) => server.setUpdate(info));
+  if (checkForUpdates) {
+    updates = watchForUpdates(__LOREWARDEN_VERSION__, (info) => server.setUpdate(info));
+  }
   if (updater) {
     void updater.refresh();
     if (checkForUpdates) updater.watch(() => server.latestRelease);
diff --git a/packages/server/src/server.ts b/packages/server/src/server.ts
index 1f59a22..a5f9d4c 100644
--- a/packages/server/src/server.ts
+++ b/packages/server/src/server.ts
@@ -26,7 +26,7 @@ import { Attempts, clientAddress } from './limits';
 import { type AuthorizationRequest, type OAuth, OAuthError } from './oauth';
 import { RevisionMismatch, type Store, type StoredAdventure } from './store';
 import type { Updater } from './updater';
-import type { UpdateInfo } from './updates';
+import type { CheckResult, UpdateInfo } from './updates';
 
 export { DEFAULT_SERVER_PORT };
 
@@ -95,6 +95,8 @@ export interface ServerOptions {
   publicUrl?: string;
   /** The optional updater container, which updates this server when asked. */
   updater?: Updater;
+  /** Asks GitHub for a newer release right away; unset when the server does not check. */
+  checkForUpdates?: () => Promise<CheckResult>;
 }
 
 interface Connection {
@@ -124,6 +126,8 @@ export class LorewardenServer {
   private server: Server | undefined;
   private port = DEFAULT_SERVER_PORT;
   private update: UpdateInfo;
+  /** The last check the game master asked for, so pressing the button again waits a minute. */
+  private lastCheck: { at: number; result: CheckResult } | undefined;
   /** Wrong passwords and setup links. */
   private readonly signIns = new Attempts(5, 15 * 60_000);
   /** Wrong join codes. */
@@ -132,7 +136,10 @@ export class LorewardenServer {
   private readonly registrations = new Attempts(10, 60 * 60_000);
 
   constructor(private readonly options: ServerOptions) {
-    this.update = { current: options.version ?? 'dev' };
+    this.update = {
+      current: options.version ?? 'dev',
+      ...(options.checkForUpdates ? { canCheck: true } : {}),
+    };
   }
 
   listen(port = DEFAULT_SERVER_PORT, host = '0.0.0.0'): Promise<number> {
@@ -702,6 +709,7 @@ export class LorewardenServer {
     }
 
     if (pathname.startsWith('/api/updater/')) return this.handleUpdater(req, res, pathname);
+    if (pathname === '/api/updates/check') return this.checkForUpdates(req, res);
 
     const sessionMatch = /^\/api\/sessions\/([^/]+)$/.exec(pathname);
     if (sessionMatch?.[1] && method === 'PUT') {
@@ -715,6 +723,17 @@ export class LorewardenServer {
     res.writeHead(404).end('Not found');
   }
 
+  /** "Check for updates" in the settings. GitHub allows few requests, so at most one a minute. */
+  private async checkForUpdates(req: IncomingMessage, res: ServerResponse): Promise<void> {
+    const { checkForUpdates } = this.options;
+    if (!checkForUpdates) return void res.writeHead(404).end('This server does not check');
+    if (req.method !== 'POST') return void res.writeHead(405).end('Method not allowed');
+    if (!this.lastCheck || Date.now() - this.lastCheck.at > 60_000) {
+      this.lastCheck = { at: Date.now(), result: await checkForUpdates() };
+    }
+    return sendJson(res, { result: this.lastCheck.result, update: this.update });
+  }
+
   /** The update button and the automatic updates in the settings. */
   private async handleUpdater(
     req: IncomingMessage,
@@ -752,8 +771,8 @@ export class LorewardenServer {
 
   /** Tells the game master app that a newer release is out. */
   setUpdate(update: UpdateInfo): void {
-    this.update = update;
-    this.broadcast('update', update);
+    this.update = { ...update, ...(this.update.canCheck ? { canCheck: true } : {}) };
+    this.broadcast('update', this.update);
   }
 
   /** The newest release, when it is newer than this server's version. */
diff --git a/packages/server/src/updates.ts b/packages/server/src/updates.ts
index c1c3cf0..848222a 100644
--- a/packages/server/src/updates.ts
+++ b/packages/server/src/updates.ts
@@ -9,6 +9,17 @@ export interface UpdateInfo {
   latest?: string;
   /** Release notes of the newest release. */
   url?: string;
+  /** Whether the server asks GitHub, so the app can offer to check now. */
+  canCheck?: boolean;
+}
+
+/** How a check ended: a newer release is out, this is the newest, or GitHub did not answer. */
+export type CheckResult = 'newer' | 'current' | 'unreachable';
+
+export interface UpdateWatcher {
+  /** Checks right away, e.g. when the game master asks in the settings. */
+  check(): Promise<CheckResult>;
+  stop(): void;
 }
 
 /** Splits "v1.2.3" into [1, 2, 3]; anything that is not a plain version is undefined. */
@@ -54,16 +65,20 @@ export function watchForUpdates(
   current: string,
   onChange: (info: UpdateInfo) => void,
   check = fetchLatestRelease,
-): () => void {
+): UpdateWatcher {
   let known: string | undefined;
-  const run = async () => {
+  const run = async (): Promise<CheckResult> => {
     const release = await check();
-    if (!release || !isNewer(release.version, current) || release.version === known) return;
-    known = release.version;
-    onChange({ current, latest: release.version, url: release.url });
+    if (!release) return 'unreachable';
+    if (!isNewer(release.version, current)) return 'current';
+    if (release.version !== known) {
+      known = release.version;
+      onChange({ current, latest: release.version, url: release.url });
+    }
+    return 'newer';
   };
   void run();
   const timer = setInterval(() => void run(), CHECK_INTERVAL_MS);
   timer.unref();
-  return () => clearInterval(timer);
+  return { check: run, stop: () => clearInterval(timer) };
 }
diff --git a/packages/server/test/server.test.ts b/packages/server/test/server.test.ts
index da6a8a9..30a7c37 100644
--- a/packages/server/test/server.test.ts
+++ b/packages/server/test/server.test.ts
@@ -553,6 +553,47 @@ describe('Lorewarden server', () => {
     const update = { current: '1.0.0', latest: '1.1.0', url: 'https://example.org/1.1.0' };
     server.setUpdate(update);
     expect(await gm.next('update')).toEqual(update);
+    // This server does not ask GitHub, so there is nothing to check now.
+    expect((await fetch(`${base}/api/updates/check`, { method: 'POST' })).status).toBe(404);
+  });
+});
+
+describe('Lorewarden server that checks for updates', () => {
+  it('checks when the game master asks, at most once a minute', async () => {
+    const dataDir = mkdtempSync(join(tmpdir(), 'lorewarden-data-'));
+    let checks = 0;
+    let server: LorewardenServer | undefined;
+    server = new LorewardenServer({
+      store: new Store(dataDir),
+      version: '1.0.0',
+      checkForUpdates: async () => {
+        checks++;
+        server?.setUpdate({ current: '1.0.0', latest: '1.1.0', url: 'https://example.org/1.1.0' });
+        return 'newer';
+      },
+    });
+    const base = `http://127.0.0.1:${await server.listen(0, '127.0.0.1')}`;
+    try {
+      const check = async () => {
+        const response = await fetch(`${base}/api/updates/check`, { method: 'POST' });
+        expect(response.status).toBe(200);
+        return response.json();
+      };
+      expect(await check()).toEqual({
+        result: 'newer',
+        update: {
+          current: '1.0.0',
+          latest: '1.1.0',
+          url: 'https://example.org/1.1.0',
+          canCheck: true,
+        },
+      });
+      expect(await check()).toMatchObject({ result: 'newer' });
+      expect(checks).toBe(1);
+    } finally {
+      await server.close();
+      rmSync(dataDir, { recursive: true, force: true });
+    }
   });
 });
 
diff --git a/packages/server/test/updates.test.ts b/packages/server/test/updates.test.ts
index 3fb9b10..9b10444 100644
--- a/packages/server/test/updates.test.ts
+++ b/packages/server/test/updates.test.ts
@@ -20,27 +20,31 @@ describe('watchForUpdates', () => {
   it('reports a newer release once', async () => {
     const onChange = vi.fn();
     const check = vi.fn(async () => ({ version: '1.1.0', url: 'https://example.org/1.1.0' }));
-    const stop = watchForUpdates('1.0.0', onChange, check);
+    const watcher = watchForUpdates('1.0.0', onChange, check);
     await vi.waitFor(() => expect(onChange).toHaveBeenCalledOnce());
     expect(onChange).toHaveBeenCalledWith({
       current: '1.0.0',
       latest: '1.1.0',
       url: 'https://example.org/1.1.0',
     });
-    stop();
+    expect(await watcher.check()).toBe('newer');
+    expect(onChange).toHaveBeenCalledOnce();
+    watcher.stop();
   });
 
   it('stays quiet when the server is up to date or GitHub cannot be reached', async () => {
     const onChange = vi.fn();
     const upToDate = vi.fn(async () => ({ version: '1.0.0', url: 'https://example.org/1.0.0' }));
     const offline = vi.fn(async () => undefined);
-    const stops = [
+    const watchers = [
       watchForUpdates('1.0.0', onChange, upToDate),
       watchForUpdates('1.0.0', onChange, offline),
     ];
     await vi.waitFor(() => expect(offline).toHaveBeenCalled());
     await vi.waitFor(() => expect(upToDate).toHaveBeenCalled());
     expect(onChange).not.toHaveBeenCalled();
-    for (const stop of stops) stop();
+    expect(await watchers[0]?.check()).toBe('current');
+    expect(await watchers[1]?.check()).toBe('unreachable');
+    for (const watcher of watchers) watcher.stop();
   });
 });