Firebase Auth vs Stytch

Firebase Auth handles email/password, social login, phone auth, and anonymous users with minimal setup. Google gives you 50,000 MAU free for most auth methods, which is five times what Clerk or Auth0 offer. If you are already using Firestore or Cloud Functions, Auth plugs in with a single line of config.

The downside is that Firebase Auth is designed to keep you inside Google’s ecosystem. Using it as a standalone auth service (say, with a Postgres database and a Next.js app on Vercel) is doable but clunky compared to Clerk or Supabase Auth. You also need to build your own login UI, since Firebase only provides a basic drop-in widget (FirebaseUI) that looks dated. For solo founders already committed to Firebase, Auth is the obvious choice. For everyone else, evaluate whether you want that Google dependency.

Stytch is built around the idea that passwords are a liability. Instead of email/password as the default, it leads with magic links, one-time passcodes, passkeys, and biometric auth. The API is well-designed: you can have passwordless login working in under an hour. It also offers fraud tools such as device fingerprinting, with 10,000 fingerprints included free. Twilio completed its purchase of Stytch on 14 November 2025, and the product continues under the Stytch name.

Pricing is pay as you go with no monthly base fee. The free tier covers 10,000 monthly active users and AI agents, unlimited organizations, 5 SSO or SCIM connections and 1,000 machine-to-machine tokens, and usage above that is billed per unit with no hard caps. Full email customization and removal of Stytch branding cost $99. If your product specifically benefits from passwordless (fewer support tickets, higher conversion on sign-up), Stytch is a strong fit. If you just need standard social login and email/password, Clerk or Firebase Auth are simpler to set up.