status: active
timestamp: 2026-06-20
tags: [auth, microsoft, oauth, primary]
Microsoft sign-in (Firebase OAuth provider)
Microsoft / Entra ID OAuth via Firebase Auth — free, unlimited, no card
Microsoft sign-in (Firebase OAuth provider)
Role
Lets a user sign in with a Microsoft personal account (outlook.com,
live.com, hotmail.com) or a work / school Entra ID tenant, against
the same oriz-app Firebase Auth project as every other provider.
Free tier
- Unlimited Microsoft sign-ins through Firebase’s
OAuthProvider('microsoft.com'). - Multi-tenant Entra ID app registration (so any Microsoft tenant works).
- No Microsoft / Azure billing required for the OAuth login flow.
Card / subscription required?
NO. Native to Firebase Auth — Spark plan covers it. The Azure-side app registration (Entra ID) is free under the standard Microsoft account; it doesn’t require an Azure subscription.
Alternatives
- Clerk — Microsoft is a one-click social provider there too
- Supabase — Microsoft via OIDC
- Skip it (only Email link / Google / GitHub / Anonymous + Passkeys)
Swap cost
Low — single <AccountPanel> button. Disabling Microsoft means
removing the OAuth provider config in Firebase Console + the button;
no schema changes.
Why this is our pick
User runs Azure for Students for free Azure credits — adding a Microsoft sign-in button keeps the auth UX aligned with where their work / classroom identity already lives. Costs nothing on top of Firebase Spark. Native to Firebase Auth, so it pairs cleanly with App Check + the same Firestore rules.
Implementation notes
- Firebase Console → Authentication → Sign-in method → enable Microsoft.
- Register an Entra ID app at https://entra.microsoft.com/ as
multi-tenant + personal accounts (
AzureADandPersonalMicrosoftAccount). - Redirect URI:
https://oriz-app.firebaseapp.com/__/auth/handler. - Store
MICROSOFT_OAUTH_CLIENT_ID+MICROSOFT_OAUTH_CLIENT_SECRETin Doppler, synced to Firebase config.