Auth & Identity
Auth.js vs Clerk
Side by side
- Pricing model
- Auth.jsFlat rate
- ClerkHybrid
- Starting price
- Auth.js$0
- ClerkFreemium
- Free tier
- Auth.jsYes — Fully free and open source
- ClerkYes
- Maturity
- Auth.jsEstablished
- Clerk—
- Availability
- Auth.jsGenerally available
- ClerkGenerally available
- Last checked
- Auth.jsOct 13, 2026
- ClerkOct 12, 2026
| Fact | Auth.js | Clerk |
|---|---|---|
| Pricing model | Flat rate | Hybrid |
| Starting price | $0 | Freemium |
| Free tier | Yes — Fully free and open source | Yes |
| Maturity | Established | — |
| Availability | Generally available | Generally available |
| Last checked | Oct 13, 2026 | Oct 12, 2026 |
When each one fits
Choose Auth.js when…
Next.js apps wanting free, self-hosted auth
Native integration, no per-user cost
Developers comfortable owning auth plumbing
Full control over sessions and providers
Auth.js strengths
Free and open source
First-class Next.js integration
Many OAuth providers built in
Choose Clerk when…
Next.js and React developers who need auth, user management, and organization features with minimal setup
Look past Clerk if…
Teams that need fully self-hosted auth or already have mature auth infrastructure
Clerk strengths
Pre-built UI components
Multi-factor auth
Organization management
Social login
SAML SSO
Webhooks
Trade-offs
Known weaknesses from each tool’s record. Sourced ones link to where they came from.
Auth.js
Token rotation is broken, causing new tokens from external IDPs to be lost and old tokens to be reused indefinitely.
The v5 release is in beta with unclear stability and security implications for production use.
Session state is not updated on the client side after sign-out, requiring manual page reloads.
JWT modification for refreshing access tokens is not possible after initial login.
Clerk
The Hobby plan restricts session lifetime to a fixed 7 days, preventing customization for security or UX requirements.
The Hobby plan limits application logs to 1 day of retention, hindering debugging and audit capabilities.
The Hobby plan restricts user impersonation to 5 per month, limiting developer testing and support workflows.
The B2B Authentication add-on limits organizations to 20 members by default, requiring an additional paid tier for larger teams.