head to head · open source
Zitadel vs smart-sso
Zitadel has 15,499 GitHub stars, 1,413 forks, 1,171 open issues and last shipped yesterday. smart-sso has 2,300 stars, 1,218 forks, 49 open issues and last shipped 4 days ago. Zitadel leads on adoption by 574% (15,499 vs 2,300 stars). Zitadel is written in Go under AGPL-3.0; smart-sso is written in Java under MIT. Zitadel has attracted 9% as many forks as stars, smart-sso 53%. Zitadel was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (authentication, authorization), 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
| Zitadel | smart-sso | |
|---|---|---|
| GitHub stars | ★ 15K | ★ 2.3K |
| License | AGPL-3.0 | MIT |
| Written in | Go | Java |
| Last push | 2026-11-02 | 2026-10-30 |
| Forks | ⑂ 1.4K | ⑂ 1.2K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Zitadel if
- You weight community size — 15K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Go
- You value the larger contributor base for long-term maintenance
pick smart-sso if
- You want the smart-sso feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Java
- You evaluated both and smart-sso fits your workflow better
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 →
About smart-sso
Smart SSO English 简体中文 Smart SSO is a lightweight authentication and authorization center (SSO) built on Spring Boot 3 and the OAuth 2.0 authorization code flow. It ships SSO login/logout, silent token renewal, forced logout, button level permissions and distributed deployment support — plus a zero dependency demo mode that starts with a single command, no database required. English guides for client integration, architecture, configuration and frequently asked questions are available under docs/ . Chinese originals remain available from the language switcher. Features 1. Lightweight — minimal implementation on…
read the full smart-sso overview →
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Frequently asked questions
Is Zitadel or smart-sso more popular?
Zitadel has 15,499 GitHub stars and smart-sso has 2,300. Zitadel has the larger community by that measure.
Are Zitadel and smart-sso free?
Both are open source. Zitadel is licensed under AGPL-3.0 and smart-sso under MIT. Neither carries a licence fee.
What is the difference between Zitadel and smart-sso?
Zitadel is written in Go and smart-sso in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Zitadel or smart-sso?
Choose Zitadel if you want the larger community (15,499 stars) or its AGPL-3.0 licence terms. Choose smart-sso if its feature set, stack or MIT licence fits better. Both are self-hostable.