head to head · open source
hydra vs smart-sso
hydra has 17,646 GitHub stars, 1,620 forks, 98 open issues and last shipped 3 months ago. smart-sso has 2,300 stars, 1,218 forks, 49 open issues and last shipped 4 days ago. hydra leads on adoption by 667% (17,646 vs 2,300 stars). hydra is written in Go under Apache-2.0; smart-sso is written in Java under MIT. hydra has attracted 9% as many forks as stars, smart-sso 53%. smart-sso was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (authorization, oauth2-provider), 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
| hydra | smart-sso | |
|---|---|---|
| GitHub stars | ★ 18K | ★ 2.3K |
| License | Apache-2.0 | MIT |
| Written in | Go | Java |
| Last push | 2026-07-29 | 2026-10-30 |
| Forks | ⑂ 1.6K | ⑂ 1.2K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick hydra if
- You weight community size — 18K stars and counting
- You want the Apache-2.0 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 hydra
Chat · Discussions · Newsletter · Docs · Try Ory Network · Jobs Ory Hydra is a hardened, OpenID Certified OAuth 2.0 Server and OpenID Connect Provider optimized for low latency, high throughput, and low resource consumption. It connects to your existing identity provider through a login and consent app, giving you absolute control over the user interface and experience. What is Ory Hydra? Why Ory Hydra OAuth2 and OpenID Connect: Open Standards OpenID Connect Certified Deployment options Use Ory Hydra on the Ory Network Self host Ory Hydra Quickstart Who is using Ory Hydra Ecosystem Ory Kratos: Identity and User…
read the full hydra 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 hydra or smart-sso more popular?
hydra has 17,646 GitHub stars and smart-sso has 2,300. hydra has the larger community by that measure.
Are hydra and smart-sso free?
Both are open source. hydra is licensed under Apache-2.0 and smart-sso under MIT. Neither carries a licence fee.
What is the difference between hydra and smart-sso?
hydra 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, hydra or smart-sso?
Choose hydra if you want the larger community (17,646 stars) or its Apache-2.0 licence terms. Choose smart-sso if its feature set, stack or MIT licence fits better. Both are self-hostable.