#1
Keycloak is an open-source IAM server providing single sign-on, user federation, and centralized authentication and authorization using OIDC, OAuth 2.0, and SAML.
36.4k stars8.9k forksApache-2.0last commit Actively maintained
8 self-hosted Stack Auth alternatives
Stack Auth is a developer-focused authentication and user-management SaaS offering login and session handling, user and organization management, APIs/SDKs for web and mobile apps, and identity integrations.
Alternatives to Stack Auth
#2
ZITADEL is an open source IAM/CIAM platform providing SSO, MFA, OIDC/OAuth2, SAML, user management, and multi-tenant organizations with audit logging.
14.9k stars1.3k forksAGPL-3.0last commit Actively maintained
#3
Open-source authentication and authorization infrastructure with OIDC/OAuth 2.1, SAML SSO, multi-tenancy, MFA, and RBAC for SaaS and AI apps.
14.5k stars1.2k forksMPL-2.0last commit Actively maintained
Pocket ID is a simple self-hosted OpenID Connect (OIDC) provider that lets users sign in to apps using passkeys instead of passwords.
9k stars304 forksBSD-2-Clauselast commit Actively maintained
#5
VoidAuth is a self-hosted SSO provider with OpenID Connect, ForwardAuth proxy auth, and built-in user and group management plus MFA and passkeys.
2.5k stars100 forksAGPL-3.0last commit Actively maintained
#6
Open-source Auth0/Clerk/Firebase Auth alternative with passkeys, MFA, SSO (OIDC/SAML), user management portal, and extensible auth flows for web and mobile apps.
2k stars125 forksApache-2.0last commit Actively maintained
Turnkey OAuth 2.0/OIDC authentication system with admin panel, REST APIs, RBAC, MFA, social login, and flexible deployment on Cloudflare Workers or Node.js.
635 stars68 forksMITlast commit Actively maintained
Lightweight Go-based authentication gateway that provides unified SSO for Plex, Jellyfin, and Emby users with OIDC, MFA and an admin console. Runs in Docker and stores profiles in Postgres.
98 stars1 forksGPL-3.0last commit Actively maintained
What replacing Stack Auth actually involves
Every option on this page is open source and free to run on your own hardware, so you own the data and there is no subscription to cancel. 8 of 8 shipped a commit in the last six months. Licences in this list: Apache-2.0, AGPL-3.0, MPL-2.0, BSD-2-Clause, MIT. In exchange you take on hosting, backups and updates yourself.
Browse everything in Identity & Access Management (IAM).
