Auth

Free and open-source Auth0 alternatives

Auth0 (Authentication and authorization platform) is a commercial product. These 4 tools do the same job and are free to use or to self-host.

Short answer: the best free alternatives to Auth0 are Keycloak, SuperTokens, Zitadel and Better Auth. Auth0 starts at $35/mo (Essentials). Self-hosting is free; you pay only for the server (a small VPS is about $4–6/mo). Licenses and prices checked 2026-10-01.

1
Keycloak
Open-source identity and access management
Identity and access management server (CNCF).
Open source (Apache-2.0) ·★ 37k GitHub stars · last commit 2026-10-07 · details
2
SuperTokens
Open-source authentication for web and mobile apps
Self-hosted auth with prebuilt UI.
Open source (Apache-2.0 (core)) ·★ 15k GitHub stars · last commit 2026-10-06 · details
3
Zitadel
Open-source identity infrastructure with SSO and multi-tenancy
Identity platform with multi-tenancy.
Open source (AGPL-3.0) ·★ 15k GitHub stars · last commit 2026-10-07 · details
4
Better Auth
Open-source authentication framework for TypeScript
TypeScript auth library that runs in your app.
Open source (MIT) ·★ 30k GitHub stars · last commit 2026-10-06 · details

Want paid options too? See all Auth0 alternatives or the full free alternatives list. Beyond developer tools, OSS Software lists more open-source Auth0 alternatives.

FAQ

Is there a free alternative to Auth0?+

Yes. Keycloak, SuperTokens, Zitadel and Better Auth do the same job for free; Keycloak, SuperTokens, Zitadel and Better Auth are open source.

What is the best open-source alternative to Auth0?+

Keycloak is the most starred on GitHub (37k stars). Identity and access management server (CNCF).

Open source: OSI-approved license. Free to self-host: the code is public and free to run yourself, with limits in the license.

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Free and open-source Auth0 alternatives

FAQ