head to head · open source
Ory vs cas
Ory has 13,883 GitHub stars, 1,186 forks, 224 open issues and last shipped 2 months ago. cas has 11,367 stars, 3,959 forks, 17 open issues and last shipped today. Ory leads on adoption by 22% (13,883 vs 11,367 stars). Ory is written in Go under Apache-2.0; cas is written in Java under Apache-2.0. Ory has attracted 9% as many forks as stars, cas 35%. cas was the more recently maintained of the two, and both are self-hostable with no licence fee.
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
| Ory | cas | |
|---|---|---|
| GitHub stars | ★ 14K | ★ 11K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Go | Java |
| Last push | 2026-07-29 | 2026-09-20 |
| Forks | ⑂ 1.2K | ⑂ 4.0K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Ory if
- You weight community size — 14K 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 cas if
- You want the cas feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and cas fits your workflow better
About Ory
Ory Kratos is headless cloud native authentication and identity management system written in Go. It sits inside Ory stack and Security & Privacy / Identity & Access Management category. It exposes identity work over HTTP APIs. Services consume login, registration, recovery, verification, profile management instead of reimplementing them.
About cas
Apereo CAS is the open source Java server that implements the Central Authentication Service protocol and serves as an enterprise identity provider and single sign on platform for the web, aimed at organizations that need one authentication and authorization layer across many applications.
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Frequently asked questions
Is Ory or cas more popular?
Ory has 13,883 GitHub stars and cas has 11,367. Ory has the larger community by that measure.
Are Ory and cas free?
Both are open source. Ory is licensed under Apache-2.0 and cas under Apache-2.0. Neither carries a licence fee.
What is the difference between Ory and cas?
Ory is written in Go and cas 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, Ory or cas?
Choose Ory if you want the larger community (13,883 stars) or its Apache-2.0 licence terms. Choose cas if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.