head to head · open source
Better Auth vs cas
Better Auth has 30,000 GitHub stars, 2,893 forks, 723 open issues and last shipped 2 days ago. cas has 11,366 stars, 3,959 forks, 17 open issues and last shipped yesterday. Better Auth leads on adoption by 164% (30,000 vs 11,366 stars). Better Auth is written in TypeScript under MIT; cas is written in Java under Apache-2.0. Better Auth has attracted 10% 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. The two share 2 topic tags (authentication, oauth2), 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
| Better Auth | cas | |
|---|---|---|
| GitHub stars | ★ 30K | ★ 11K |
| License | MIT | Apache-2.0 |
| Written in | TypeScript | Java |
| Last push | 2026-09-17 | 2026-09-18 |
| Forks | ⑂ 2.9K | ⑂ 4.0K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Better Auth if
- You weight community size — 30K stars and counting
- You want the MIT license terms
- Your stack matches TypeScript
- 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 Better Auth
Better Auth is a framework agnostic authentication and authorization framework written in TypeScript. It targets the broader JavaScript/TypeScript ecosystem and is designed to integrate with any backend or frontend framework, including Next.js, Express, SvelteKit, and others. It provides a unified API surface for core identity workflows such as sign up, sign in, session management, and passwordless flows.
read the full Better Auth overview →
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 Better Auth or cas more popular?
Better Auth has 30,000 GitHub stars and cas has 11,366. Better Auth has the larger community by that measure.
Are Better Auth and cas free?
Both are open source. Better Auth is licensed under MIT and cas under Apache-2.0. Neither carries a licence fee.
What is the difference between Better Auth and cas?
Better Auth is written in TypeScript 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, Better Auth or cas?
Choose Better Auth if you want the larger community (30,000 stars) or its MIT licence terms. Choose cas if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.