Firebase services silently hang in Safari with multiple tabs open (no errors thrown)

[davidko5]

Operating System

macOS 26.3.1 (25D2128)

Environment (if applicable)

Safari 26.3

Firebase SDK Version

11.6.0

Firebase SDK Product(s)

Remote-Config, Auth, Functions, AppCheck, Database

Project Tooling

Next.js 15 (App Router), React 19, TypeScript

Detailed Problem Description

Our web app (skinape.com) uses Auth, Functions, RTDB, Remote Config, and App Check. We noticed that after keeping Safari open with ~15 tabs of our app, some Firebase services stop functioning. Checking at random intervals (sometimes after hours, sometimes overnight), we find that reloading a tab results in infinite loading states on various routes (/app, /app/earn, /app/shop/skins, /app/shop/giftcards).

The set of affected services varies between incidents — sometimes auth doesn't work but other services do, sometimes Functions and RTDB are broken but auth is fine, sometimes only Remote Config hangs, sometimes all four are affected.

No Firebase-related errors appear in the console. HAR file exports from the broken state show that the Firebase SDK doesn't make certain network requests at all — depending on the incident, this can be zero Function calls, zero auth token requests, zero RTDB connections, or any combination. HAR files from the same browser after recovery show all requests succeeding normally. We can provide these HAR files if helpful.

Closing and reopening the browser resolves the issue. In one case, closing most of the open tabs resolved it as well. Incognito mode works normally.

From our error tracking (Sentry), we see similar loading states reported not only on Safari but also on other systems like Windows with Edge. We haven't confirmed those are the exact same issue.

Changes we tried:

• initializeAuth with browserLocalPersistence — suspected auth hang was blocking other services. Auth timeouts in error tracking reduced but not eliminated.
• Disabled initializeAppCheck — issue first noticed Dec 10, two days after adding App Check (Dec 8). Disabled to test correlation.
• Both applied — in latest incident, Functions and auth worked but Remote Config still hung.

The varying broken states across incidents make it hard to attribute the problem to a single service. It appears that each Firebase service using IndexedDB can independently get stuck when Safari's IndexedDB enters a hung state. A way to handle this gracefully — so the application can degrade instead of hanging indefinitely without any error — would be very helpful.

Related issues: #7888, #8019, #8860

Steps and code to reproduce issue

1. Open ~15 tabs of skinape.com in Safari on macOS
2. Check at random intervals (try reloading several tabs every hour or so)
3. At some point, one or more tabs will enter the broken state — infinite loading on /app, /app/earn, /app/shop/skins, /app/shop/giftcards. No Firebase-related errors in console.
4. Reproduction is not deterministic — it appears related to Safari's IndexedDB connection management across tabs over time

Our Firebase initialization and usage:

const app = initializeApp(firebaseConfig);

// Auth — switched to localStorage to work around IndexedDB hang (#7888)
const auth = initializeAuth(app, {
  persistence: browserLocalPersistence,
  popupRedirectResolver: browserPopupRedirectResolver,
});

// App Check — currently disabled for testing
// initializeAppCheck(app, {
//   provider: new ReCaptchaV3Provider(siteKey),
//   isTokenAutoRefreshEnabled: true,
// });

const db = getDatabase(app);
const functions = getFunctions(app);
const remoteConfig = getRemoteConfig(app);

// This promise never resolves when in the broken state
const remoteConfigReady = fetchAndActivate(remoteConfig);

// Every Remote Config read awaits this promise
const getValueRemoteConfig = async (key: string) => {
  await remoteConfigReady;
  return getValue(remoteConfig, key);
};

[DellaBitta]

Hi @davidko5,

We have indeed seen users run into systemic issues with IndexedDB hanging in Safari, especially with multiple tabs open. I see in your "Changes we tried" that you already moved Auth to browserLocalPersistence to mitigate this. Unfortunately, because the other Firebase SDKs you are using (like Remote Config and Functions) also rely heavily on IndexedDB under the hood, they will still get caught in that same Safari-level lockup, as you noted.

You mentioned that you are seeing similar infinite loading states on Windows with Edge via Sentry. Since Edge is Chromium-based, this is very interesting. Do you happen to have any more information about these Windows Edge occurrences?

If this is strictly a Safari issue, it unfortunately points to an underlying WebKit/Safari IndexedDB implementation bug that limits what we can do on the SDK side. However, if you can provide a reliable reproduction — or give us more data on the Windows/Edge failures — we can certainly investigate further to see if there's a broader SDK issue here.

Thanks!

[google-oss-bot]

Hey @davidko5. We need more information to resolve this issue but there hasn't been an update in 5 weekdays. I'm marking the issue as stale and if there are no new updates in the next 5 days I will close it automatically.

If you have more information that will help us get to the bottom of this, just add a comment!

[davidko5]

Hi @DellaBitta

I understand that you may not do much about Safari caused bug but maybe you can at least recommend any good handling for this situation? I suppose since it is known issue you should have a set of recommended handling techniques/

How can we programmatically fix this at the moment for our users? Maybe we can some how influence broken indexeddb state?
Or at least is there any way that our users can fix that for themselves?

And also could you help with some reliable way to programmatically identify that app is having this issue? so we can at least reliably show some ui to the user and log this issue reliably. Because currently there is no specific error thrown during such situations and we identify such states by monitoring sentry replays.