Fix Firebase Auth to Use Custom Domain Instead of Firebase Default
Budget: $10 – $30 USD
I have a web application hosted on Firebase, using Firebase Authentication with Google Sign-In. The issue is that when users click "Sign in with Google", they are shown this message:
"Choose an account to continue to example-app.firebaseapp.com"
What I need is for this message to show my custom domain (e.g., www.myplatform.com) instead of the default Firebase domain.
?️ Tech Stack
Firebase Hosting
Firebase Authentication (v10.7.1)
Firebase Functions (with custom reCAPTCHA logic)
Vanilla JavaScript (no frameworks)
HTML + CSS
SweetAlert2
Google reCAPTCHA v2
Custom Domain (e.g., www.myplatform.com)
❗ Current Issues
Getting a redirect_uri_mismatch error when using Google Sign-In
Even when login works, the screen still shows the Firebase domain (*.firebaseapp.com), instead of my custom domain
✅ What I've Already Done
Added all custom domains (e.g., www.myplatform.com, myplatform.com, auth.myplatform.com) in Firebase Authorized Domains
Configured OAuth redirect URIs in Google Cloud Console:
https://www.myplatform.com/__/auth/handler
https://myplatform.com/__/auth/handler
authDomain in the Firebase config is set to the custom domain
Tried both signInWithPopup() and signInWithRedirect()
Everything else in the app works fine, only Google Sign-In is having issues
?? What I Need From You
Fix the redirect_uri_mismatch error for Google Sign-In
Ensure that the Google login screen shows my custom domain, not the Firebase default
Explain what changes were needed (for future reference)
Set up the OAuth consent screen in Google Cloud Console, if necessary
Make sure it works both locally and in production
? Extras
Looking for someone who:
Has previous experience configuring Firebase Auth + custom domains
Knows how to set up Google Cloud OAuth properly
Can clearly explain what was done
Bonus if you speak Portuguese ?? (not required)
⏱️ Timeline
As soon as possible. The platform is live and this issue is currently blocking users from signing in via Google.
"Choose an account to continue to example-app.firebaseapp.com"
What I need is for this message to show my custom domain (e.g., www.myplatform.com) instead of the default Firebase domain.
?️ Tech Stack
Firebase Hosting
Firebase Authentication (v10.7.1)
Firebase Functions (with custom reCAPTCHA logic)
Vanilla JavaScript (no frameworks)
HTML + CSS
SweetAlert2
Google reCAPTCHA v2
Custom Domain (e.g., www.myplatform.com)
❗ Current Issues
Getting a redirect_uri_mismatch error when using Google Sign-In
Even when login works, the screen still shows the Firebase domain (*.firebaseapp.com), instead of my custom domain
✅ What I've Already Done
Added all custom domains (e.g., www.myplatform.com, myplatform.com, auth.myplatform.com) in Firebase Authorized Domains
Configured OAuth redirect URIs in Google Cloud Console:
https://www.myplatform.com/__/auth/handler
https://myplatform.com/__/auth/handler
authDomain in the Firebase config is set to the custom domain
Tried both signInWithPopup() and signInWithRedirect()
Everything else in the app works fine, only Google Sign-In is having issues
?? What I Need From You
Fix the redirect_uri_mismatch error for Google Sign-In
Ensure that the Google login screen shows my custom domain, not the Firebase default
Explain what changes were needed (for future reference)
Set up the OAuth consent screen in Google Cloud Console, if necessary
Make sure it works both locally and in production
? Extras
Looking for someone who:
Has previous experience configuring Firebase Auth + custom domains
Knows how to set up Google Cloud OAuth properly
Can clearly explain what was done
Bonus if you speak Portuguese ?? (not required)
⏱️ Timeline
As soon as possible. The platform is live and this issue is currently blocking users from signing in via Google.