Open Source Alternatives
Open Source Auth Alternatives to Clerk
Developer-first authentication and user management with prebuilt React/Next.js UI components.
Clerk is a trademark of its respective owner.
Updated May 2026
What you gain
- ✓No per-monthly-active-user pricing that scales with every signup
- ✓Your user records and sessions live in your own database
- ✓Self-hosted auth so user data never leaves your infrastructure
- ✓No vendor lock-in on your identity provider
What you give up
- △No drop-in SignIn and UserButton React components, you build the UI
- △No built-in organizations, invitations, and roles UI out of the box
- △Fewer prebuilt social-login connectors wired up for you
- △No managed bot protection on the sign-in flow
Switching Cost
Clerk's lock-in is the prebuilt UI, not your users. Accounts and sessions export, and SuperTokens or Logto give you the same auth primitives, but Clerk's drop-in React components are the thing you actually rebuild. A solo dev on a side project swaps in a day. A team that leaned on Clerk's organizations, invitations, and prebuilt flows should budget a week or two to rebuild that UI and wire social logins. The hidden cost is re-implementing the polished sign-in experience users already expect.
| SuperTokens | Logto | ZITADEL | |
|---|---|---|---|
| Overlap | 75% | 75% | 70% |
| Migration | moderate | moderate | moderate |
| License | Apache License 2.0 | Mozilla Public License 2.0 | GNU Affero General Public License v3.0 |
| Best for | Small teams | Small teams | Small teams |
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Drop-in Replacements
Ranked by feature coverage
SuperTokens
8175% coverageOpen source alternative to Auth0/Firebase Auth/Cognito
SuperTokens is the open source authentication platform: signup, password reset, social login, multi-factor auth, without Auth0 prices or Firebase lock-in. It handles session management, email verification, passwordless login, and social OAuth out of the box.
Logto
7675% coverageAuth infrastructure for SaaS and AI apps
Logto is an auth platform you can self-host for free or use their cloud: login, signup, SSO, MFA, and user management for SaaS apps. Drop in their SDK, get a polished login experience, manage users through their admin console, done.
ZITADEL
7370% coverageIdentity infrastructure, simplified
ZITADEL is a self-contained identity platform: login, signup, SSO, multi-factor auth, user roles, all in one. It's an alternative to Auth0 or Clerk that you can self-host for free.
Authentik
8165% coverageFlexible identity provider
SSO (single sign-on), multi-factor auth, user directories, all in one place. The open source version is extremely capable.
SuperTokens, Logto, Authentik, ZITADEL, and Ory Kratos all replace the auth engine. What none give you for free is Clerk's drop-in React/Next.js components. You build the sign-in UI yourself.
OSS covers
- ✓authentication
- ✓user management
- ✓session management
OSS does not cover
- △prebuilt React UI components
- △managed bot protection
- △hosted user dashboard
Building Blocks
Clerk is a platform. It bundles multiple capabilities into one subscription. These tools each cover one piece. Teams often assemble 2–3 of them instead of paying for the full suite.
AWS Cognito