Auth.js vs Clerk: Features, Pricing and User Reviews 2026

Auth.js is completely free to use with no pricing tiers or hidden costs. As an open-source project, it is licensed under the ISC license, which allows anyone to use, modify, and distribute the software freely for both personal and commercial projects.

There are no subscription fees, no usage limits, and no charges for any features. All capabilities, including support for unlimited providers, database integrations, and advanced security features, are available at no cost. This makes Auth.js an excellent choice for projects of any size, from small personal websites to large enterprise applications.

The project is maintained by a community of contributors and is now part of Better Auth Inc. Developers can contribute to the project, report issues, and access community support through GitHub discussions completely free of charge.

Clerk offers flexible pricing to support projects of all sizes. The free plan includes 10,000 monthly active users with all core features, pre-built components, and custom domain support. Users who sign up but never return are completely free.

The Pro plan charges just $0.02 per monthly active user after your first 10,000 free users. Pro includes removing Clerk branding, allowlist and blocklist features, and customizable session duration.

For advanced needs, add-ons cost $100 per month each. The Enhanced Authentication add-on provides multi-factor auth, device tracking, and enterprise SSO. The Enhanced Administration add-on includes user impersonation and audit logs.

Organizations start at $1 per monthly active organization after your first 100 free, with unlimited members per organization in Pro.

Enterprise plans offer custom pricing with 99.99% uptime guarantees, support SLAs, HIPAA compliance, dedicated Slack support, and onboarding assistance. Startup discounts are available through partners like Y Combinator and Stripe Atlas.