What should I use if I need social login on iOS, Android, and web with the same backend?

If you need social login on iOS, Android, and web with one shared backend, the most common and clean approach is:

Use OAuth 2.0 / OpenID Connect through an auth provider

Pick an identity platform that supports:

• iOS
• Android
• Web
• Backend token verification
• Social providers like Google, Apple, Facebook, etc.

Good options

• Firebase Authentication — easiest if you want quick setup and social logins across mobile + web
• Auth0 — very flexible, good for enterprise/custom flows
• AWS Cognito — good if you’re already in AWS, but setup is more complex
• Supabase Auth — simpler developer experience, decent for modern apps
• Clerk — polished UX, strong for web/mobile depending on your stack

Recommended architecture

1. User signs in with a social provider on the client.
2. The auth provider returns an ID token / access token.
3. Your backend verifies that token.
4. Your backend creates/uses its own session or user record.

This way:

• each platform uses the same login system
• your backend remains the source of truth for app-specific data
• you don’t have to build separate social login logic for every platform

If you want the simplest choice

• Firebase Auth is usually the easiest for a cross-platform app.
• Auth0 is often better if you need more control, enterprise features, or complex auth rules.

If you’re building your own backend

Don’t implement social login by storing passwords yourself. Instead:

• use OAuth/OIDC
• verify provider-issued tokens server-side
• map provider identities to your internal user IDs

Important note

For Apple Sign In, if you support any social login on iOS, Apple may require “Sign in with Apple” as an option too.

If you want, I can recommend the best choice based on your stack:

• Flutter / React Native / native iOS+Android
• backend language/framework
• whether you need enterprise SSO or just consumer social login