head to head · open source
hydra vs polis
hydra has 17,566 GitHub stars, 1,610 forks, 98 open issues and last shipped 2 months ago. polis has 2,266 stars, 234 forks, 35 open issues and last shipped 2 months ago. hydra leads on adoption by 675% (17,566 vs 2,266 stars). hydra is written in Go under Apache-2.0; polis is written in TypeScript under Apache-2.0. hydra has attracted 9% as many forks as stars, polis 10%. hydra was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (hacktoberfest), 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 | polis | |
|---|---|---|
| GitHub stars | ★ 18K | ★ 2.3K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Go | TypeScript |
| Last push | 2026-07-29 | 2026-07-27 |
| Forks | ⑂ 1.6K | ⑂ 234 |
| 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 polis if
- You want the polis feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and polis fits your workflow better
About hydra
Ory Hydra is an OpenID Certified OpenID Connect and OAuth 2.1 provider written in Go and licensed under Apache 2.0, built for teams that need standards compliant token issuance, client management, and consent flows while user accounts stay in their own existing identity system.
read the full hydra overview →
About polis
Ory Polis is an open source, Apache 2.0 licensed single sign on service that bridges SAML login flows to OAuth 2.0 or OpenID Connect and adds SCIM 2.0 directory sync, aimed at developers and platform teams that need enterprise authentication and automated user provisioning in web applications without implementing those protocols themselves.
read the full polis overview →
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Frequently asked questions
Is hydra or polis more popular?
hydra has 17,566 GitHub stars and polis has 2,266. hydra has the larger community by that measure.
Are hydra and polis free?
Both are open source. hydra is licensed under Apache-2.0 and polis under Apache-2.0. Neither carries a licence fee.
What is the difference between hydra and polis?
hydra is written in Go and polis in TypeScript. 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 polis?
Choose hydra if you want the larger community (17,566 stars) or its Apache-2.0 licence terms. Choose polis if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.