Clerk provides prebuilt auth, user management, and SSO for developers. Compare pricing plans, MAU limits, features, pros, cons, and alternatives.
Clerk was founded in 2019 by twin brothers Braden Sidoti and Colin Sidoti in San Francisco to give application developers a faster path to production-ready authentication than building it themselves or integrating a heavier legacy identity platform. The product combines prebuilt, customizable UI components with backend user-management infrastructure, so teams can add sign-up, sign-in, profile management, and organizations to an app without owning the underlying security logic.
Clerk has grown to support most major web frameworks, with especially deep integration for React-based stacks like Next.js and Remix, and now serves startups through large engineering teams that need enterprise identity features such as SAML and SSO without switching to a dedicated identity provider.
Clerk ships drop-in UI components for sign-up, sign-in, user profile, and organization management that can be styled to match an application's design, along with lower-level SDKs and APIs for teams that want to build fully custom interfaces on top of Clerk's auth backend. It supports multi-factor authentication, social login providers, and passkeys alongside traditional email/password flows.
Enterprise identity protocols, SAML, OIDC, and SSO, are included on every paid tier rather than reserved for the top plan, and Clerk supports multi-tenant "organizations" out of the box for B2B SaaS applications that need to manage teams and roles within a single account structure.
Clerk's Hobby plan is free and includes up to 50,000 Monthly Retained Users (MRUs) per application, unlimited applications, and up to three dashboard seats. The Pro plan is $25/month ($20/month billed annually), includes the same 50,000 MRU allotment with overages at $0.02 per additional MRU, and adds branding removal and MFA; enterprise SSO connections and custom session lifetime are available as $75/month add-ons.
The Business plan is $300/month ($250/month billed annually) and adds a SOC 2 report, priority support, 30-day log retention, and ten dashboard seats. Enterprise pricing is custom and adds a 99.99% uptime SLA, HIPAA/BAA support, custom log retention, and SIEM integration.
Yes. Clerk's Hobby plan is free and includes up to 50,000 Monthly Retained Users (MRUs) per application, unlimited applications, and up to three dashboard seats.
An MRU is a user who returns to the application more than 24 hours after signing up, similar to but stricter than a typical Monthly Active User (MAU) metric used by other platforms.
Yes, and unlike many competitors, Clerk includes SAML, OIDC, and enterprise SSO on all of its paid tiers rather than only its most expensive Enterprise plan.
Clerk provides SDKs for React, Next.js, Remix, and other modern web frameworks, along with APIs for custom integrations.
Beyond the included 50,000 MRUs on the Pro plan, additional users are billed at $0.02 per MRU. The Business plan costs $300/month ($250/month annually) with volume pricing on overages, and Enterprise is custom-priced.
Clerk is best suited for startups and product teams building modern web applications, particularly React-based apps, that want production-ready authentication without building it in-house.