The Best Firebase Authentication Alternatives in 2026
By The Alt Auth Team
Firebase Authentication is many developers’ first auth provider, and it earns that spot. At the time of writing (October 2026), standard sign-in methods are free for up to 50,000 monthly active users on both the Spark and Blaze plans; SAML and OpenID Connect sign-in are free for 50 monthly active users, with Google Cloud Identity Platform pricing above those limits; and phone sign-in is billed per SMS. Some limits also depend on your plan — address-verification emails, for example, are capped at 1,000 a day on Spark. Why move? Usually because the login needs to look fully like your product, because you want your users’ data in the EU, or because the rest of your stack is not on Google Cloud. Here are five alternatives.
1. Alt Auth — a branded login that works with any stack
Alt Auth is a hosted sign-up, sign-in and password-reset flow that carries your brand, with a dashboard to manage users, roles and organizations. You send users to your login page; they come back with a one-time code your backend exchanges for their details and a signed session token. Nothing to install, no SDK to adopt, and no cloud you have to be on. Passwords are stored as salted bcrypt hashes, every connection is encrypted, and data is stored in the EU (Frankfurt and Stockholm), run by WeNoCode OÜ in Estonia.
- Hobby, free: up to 1,000 active users a month, email/password and Google sign-in.
- Starter, $29: 10,000 included, $0.015 per extra user, your logo and colours, two-step verification.
- Growth, $99: 30,000 included, $0.010 per extra, full design control, Facebook sign-in, sign-in links by email, your own web address.
- Business, $299: 100,000 included, $0.008 per extra, unlimited apps and team members.
- Honest gap: Firebase’s free allowance is much larger, and it supports phone sign-in plus Apple, Microsoft, GitHub, X and Yahoo today. Apple and Microsoft sign-in are coming soon on Alt Auth.
“Free is a great price for a prototype. For a product, what matters is whether the login looks like you and where your users’ data lives.”— The Alt Auth Team
2. Supabase Auth — the open-source Firebase alternative
Supabase is the closest like-for-like swap: a Postgres database and an MIT-licensed auth server that supports passwords, magic links, one-time codes, social login, SAML SSO and multi-factor authentication. The free plan includes 50,000 monthly active users (free projects are paused after a week of inactivity); Pro is $25 a month with 100,000 included and $0.00325 per extra.
3. Clerk — for React and Next.js apps
Clerk’s drop-in components get a React app to working sign-in quickly, and its free plan includes 50,000 monthly retained users per app. Pro, at $25 a month, adds two-step verification, passkeys and removal of Clerk branding.
4. Auth0 — for enterprise requirements
If you are leaving Firebase because enterprise customers want SSO, organizations and compliance paperwork, Auth0 is built for that. Its free plan covers up to 25,000 monthly active users; paid plans start at $35 a month for consumer apps and $150 for B2B, for 500 active users.
5. Better Auth — for full ownership
Better Auth is an MIT-licensed TypeScript framework that stores users in your own database (PostgreSQL, MySQL, SQLite, MongoDB and more via adapters). No per-user fee and no vendor — in exchange, you operate and secure it yourself.
Moving users off Firebase
Whichever you choose, plan the migration before you switch: export users, check how their passwords are hashed, and decide whether people re-set passwords or are moved over on their next sign-in. On Alt Auth, user import is available from Starter.
See the best Supabase Auth alternatives →
See the full Alt Auth vs Firebase Authentication comparison →