Best Open Source Authentication & Identity in 2026
Solutions for managing user authentication, single sign-on, and identity verification across applications.
The most popular pick this year is Keycloak with 34,339 GitHub stars, but all 3 options below are worth considering depending on your needs.
3 open source authentication & identity — ranked by GitHub stars. Browse all
Keycloak
Open-source identity and access management with SSO, OAuth2, OIDC, and SAML support for modern applications.
Auth0
SuperTokens
Open-source authentication solution, an alternative to Auth0 and Firebase Auth that you can self-host.
Auth0
Stack Auth
Open-source authentication platform for Next.js and React, built as an alternative to Auth0 and Clerk.
Auth0How we rank these tools
Tools are ranked by GitHub stars as a proxy for community adoption and trust. Stars reflect how many developers found a project valuable enough to bookmark — a reasonable signal for quality in the open source world. We only list tools that are actively maintained and open source.
Looking for tools you can run yourself? Browse self-hosted authentication & identity →