Do I need a managed auth provider for mobile login?

Not necessarily.

You don’t need a managed auth provider for mobile login, but it’s often the easiest and safest option if you want to move quickly.

When you do want one

A managed provider like Auth0, Firebase Auth, Cognito, Clerk, Supabase Auth is a good fit if you want:

• email/password login, social login, password reset, MFA
• secure token handling without building it yourself
• account recovery, user management, brute-force protection
• less backend/auth security work

When you don’t need one

You can build your own auth if:

• you already have a backend with auth/session support
• you need full control over flows, data, or compliance
• you’re okay handling password storage, token issuance, refresh, revocation, and abuse prevention
• your app is simple and you have the engineering time to maintain it

Mobile-specific note

For mobile apps, auth usually means:

• the app signs in the user
• your backend returns a short-lived access token and often a refresh token
• the app stores secrets in Keychain (iOS) / Keystore (Android)

A managed provider helps a lot here because mobile auth has extra pitfalls around:

• token storage
• refresh flows
• social login redirect handling
• secure logout and revocation

Practical recommendation

• Solo/small team, want speed: use a managed provider.
• Need custom auth and have security expertise: build your own.
• Already using an identity system at work: integrate with that (OAuth/OIDC/SAML as needed).

If you tell me your stack (iOS/Android/React Native/Flutter + backend), I can recommend the simplest auth setup.