Firebase Auth errorFirebase Auth: auth/popup-closed-by-user

Rather not fix it yourself? App Fix Ticket starts with a fixed-price diagnosis, then a fixed price for the fix before any fix work.

Why the popup closes, and the fix

1. 01

   The user closed the popup

   “The popup has been closed by the user before finalizing the operation.” Firebase, Firebase JS SDK auth errors (POPUP_CLOSED_BY_USER)

   Closing the Google or Apple window is a normal cancel. Catch it and leave the sign-in buttons as they were.

   import { getAuth, signInWithPopup, GoogleAuthProvider } from 'firebase/auth';
   
   try {
     await signInWithPopup(getAuth(), new GoogleAuthProvider());
   } catch (error) {
     if (error.code === 'auth/popup-closed-by-user') return; // user cancelled
     showError(error);
   }

2. 02

   A COOP header on the page (commonly reported)

   Developers commonly report this error with Cross-Origin-Opener-Policy set to same-origin, which keeps the page from tracking the popup. If your hosting sets that header, try same-origin-allow-popups on pages that sign in and test again.

3. 03

   The app runs in an in-app browser

   In practice, browsers inside other apps often handle popups badly. signInWithRedirect is an alternative there, but it needs the setup in Firebase’s redirect best practices to work in browsers that block third-party storage.

4. 04

   The popup was slow to finish

   Also check: a sign-in popup that loads slowly invites users to close it. Test the flow on a slow connection and keep the work before signInWithPopup short.

Checked against the vendor’s docs on November 9, 2026: Firebase JS SDK source: auth errors; Firebase docs: Best practices for signInWithRedirect.

Rather hand it over?

Fixed scope, fixed price, paid upfront. The work happens in writing; no call needed.

• from $450App Fix TicketOne reproducible bug in an existing mobile or web app, diagnosed and fixed.See scope and start
• from $450AI-Built App RescueA Lovable, Bolt or Cursor app checked end to end in 3 days, then its worst problems fixed at a fixed price.No issues worth fixing, no charge. If the Launch Check finds nothing rated medium or higher, Simon refunds the full $450. You keep the report either way. This applies to the first 10 Launch Checks bought after October 30, 2026.See scope and start

Related: Firebase Google sign-in popup blocked · Firebase auth/cancelled-popup-request · Firebase auth/unauthorized-domain · Firebase user-token-expired