head to head · open source
Ory vs cas
Ory has 13,949 GitHub stars, 1,212 forks, 224 open issues and last shipped 3 months ago. cas has 11,394 stars, 3,955 forks, 17 open issues and last shipped yesterday. Ory leads on adoption by 22% (13,949 vs 11,394 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 | 2026-11-04 |
| 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
Chat · Discussions · Newsletter · Docs · Try Ory Network · Jobs Ory Kratos is an API first identity and user management system for cloud native applications. It centralizes login, registration, recovery, verification, and profile management flows so your services consume them instead of reimplementing them. Table of contents What is Ory Kratos? Why Ory Kratos Migrating from Auth0, Okta, and similar providers Deployment options Use Ory Kratos on the Ory Network Self host Ory Kratos Quickstart Who is using it? What is Ory Kratos? Ory Kratos is an API first identity and user management system that follows cloud…
About cas
Central Authentication Service (CAS) [ ][casslack] [ ][cassupport] Introduction Welcome to the home of the [Central Authentication Service project][apereocas], more commonly referred to as CAS. CAS is an enterprise multilingual identity provider and single sign on solution for the web and attempts to be a comprehensive platform for your authentication and authorization needs. CAS is an open and well documented authentication protocol. The primary implementation of the protocol is an open source Java server component by the same name hosted here, with support for a plethora of additional authentication protocols…
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Frequently asked questions
Is Ory or cas more popular?
Ory has 13,949 GitHub stars and cas has 11,394. 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 (13,949 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.