Open Source Auth & Identity alternatives in 2026
Single sign-on, SSO and identity management without relying on Auth0 or Okta.
Quick comparison
Sorted by featured first, then GitHub stars as a tiebreaker — the same rule we use across the whole site.
| Tool | License | Minimum RAM | GPU | Docker | GitHub |
|---|---|---|---|---|---|
| Keycloak Lightest option100% FOSSMost popular on GitHub | Apache-2.0 | ~256MB | — | ✅ | ★ ~36,500 |
| Authentik | MIT | ~2GB | — | ✅ | ★ ~25,300 |
| Headscale Lightest option100% FOSS | BSD-3-Clause | ~256MB | — | ✅ | ★ ~24,000 |
| WireGuard Easy Lightest option100% FOSS | AGPL-3.0 | ~256MB | — | ✅ | ★ ~23,000 |
| SuperTokens | Apache-2.0 | ~1GB | — | ✅ | ★ ~15,300 |
| Zitadel 100% FOSS | AGPL-3.0 (con excepciones Apache-2.0/MIT en algunos directorios) | ~1GB | — | ✅ | ★ ~14,900 |
| Logto 100% FOSS | MPL-2.0 | ~1GB | — | ✅ | ★ ~14,500 |
| Ory 100% FOSS | Apache-2.0 | ~1GB | — | ✅ | ★ ~13,900 |
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Build my stackDetailed profile of each alternative
Alternative to Auth0, Okta
Open source SSO and identity management, an alternative to Auth0/Okta.
Alternative to Okta, Auth0
Flexible identity platform, a modern alternative to Okta/Auth0.
Alternative to Auth0, Cognito
API-first identity suite, an alternative to Auth0/Cognito.
Alternative to Auth0, Okta
All-in-one multi-tenant identity, an alternative to Auth0/Okta.
Alternative to Auth0, Clerk
Authentication with ready-to-integrate SDKs, an alternative to Auth0/Clerk.
Alternative to Auth0, Clerk
Modern, easy-to-use identity, a self-hosted alternative to Clerk/Auth0.
Alternative to Tailscale
Self-hosted coordination server compatible with Tailscale.
Alternative to NordVPN Teams, OpenVPN Access Server
Web panel for your own WireGuard server, no command line needed.
Alternative to Okta
SSO and 2FA layer for your reverse proxy, a lightweight alternative to Okta.
Alternative to Okta
Lightweight OIDC server focused on passkeys, no passwords.
Frequently asked questions
Which Auth & Identity tools are 100% free?
6 out of 8 are 100% FOSS. The rest are Open-Core: the core is free, but some advanced feature may stay paid — we call it out on each tool's page.
Do I need a GPU to use these tools?
No, none of the 8 tools in this category need a GPU — they all run fine on CPU alone.
How much RAM do I need at minimum?
The lightest option on this list is Keycloak, which runs on as little as 256MB of RAM — enough for a cheap VPS.