Clerk

What is Clerk?

Clerk is a drop-in authentication product covering both the UI (sign-in, sign-up, user profile screens) and the backend user/org management behind it. It's built for speed: prebuilt components handle the screens most teams would otherwise spend real time building and securing themselves, including SSO, without writing your own auth UI.

Key features

• Prebuilt, customizable UI components for sign-in, sign-up, and user profile management
• Organization/multi-tenancy support built in, not bolted on separately
• SSO support without needing to build custom enterprise auth flows
• Session management and middleware designed specifically around frameworks like Next.js
• Webhooks and a management API for syncing user data into your own systems

Who it's for

Probably the fastest path to real, production-grade auth including SSO, if you don't want to build or maintain your own auth screens. If full ownership of your auth code and data matters more than speed, Better Auth or Auth.js keep everything in your own infrastructure instead.

Pricing

Free tier for a limited number of monthly active users, with paid plans scaling by MAU and gated features like advanced SSO. Check the site for current limits.