head to head · open source
Keycloak vs Zitadel
Keycloak has 37,657 GitHub stars, 9,129 forks, 3,292 open issues and last shipped yesterday. Zitadel has 15,499 stars, 1,413 forks, 1,171 open issues and last shipped yesterday. Keycloak leads on adoption by 143% (37,657 vs 15,499 stars). Keycloak is written in Java under Apache-2.0; Zitadel is written in Go under AGPL-3.0. Keycloak has attracted 24% as many forks as stars, Zitadel 9%. Keycloak was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (oidc), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Keycloak | Zitadel | |
|---|---|---|
| GitHub stars | ★ 38K | ★ 15K |
| License | Apache-2.0 | AGPL-3.0 |
| Written in | Java | Go |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 9.1K | ⑂ 1.4K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Keycloak if
- You weight community size — 38K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Java
- You value the larger contributor base for long-term maintenance
pick Zitadel if
- You want the Zitadel feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches Go
- You evaluated both and Zitadel fits your workflow better
About Keycloak
Open Source Identity and Access Management Add authentication to applications and secure services with minimum effort. No need to deal with storing users or authenticating users. Keycloak provides user federation, strong authentication, user management, fine grained authorization, and more. Help and Documentation Documentation User Mailing List Mailing list for help and general questions about Keycloak Join keycloak for general questions, or keycloak dev on Slack for design and development discussions, by creating an account at Reporting Security Vulnerabilities If you have found a security vulnerability, please…
read the full Keycloak overview →
About Zitadel
The Identity Infrastructure for Developers ZITADEL is an open source identity and access management platform built for teams that need more than basic auth. Whether you're securing a SaaS product, building a B2B platform, or self hosting a production IAM stack — ZITADEL gives you everything out of the box: SSO, MFA, Passkeys, OIDC, SAML, SCIM, and a battle tested multi tenancy model. No vendor lock in. No compromise on control. Just a robust, API first identity platform you can own. 🏡 Website 💬 Chat 📋 Docs 🧑💻 Blog 📞 Contact Why ZITADEL We built ZITADEL to handle the hardest IAM challenges at scale —…
read the full Zitadel overview →
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Frequently asked questions
Is Keycloak or Zitadel more popular?
Keycloak has 37,657 GitHub stars and Zitadel has 15,499. Keycloak has the larger community by that measure.
Are Keycloak and Zitadel free?
Both are open source. Keycloak is licensed under Apache-2.0 and Zitadel under AGPL-3.0. Neither carries a licence fee.
What is the difference between Keycloak and Zitadel?
Keycloak is written in Java and Zitadel in Go. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Keycloak or Zitadel?
Choose Keycloak if you want the larger community (37,657 stars) or its Apache-2.0 licence terms. Choose Zitadel if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.