Better Auth is a framework-agnostic TypeScript authentication library that developers embed directly into their own app and database, rather than a hosted service — it's already open source itself, so teams usually look for alternatives when they want a different architecture, like a standalone auth server or passkey-first flows instead of a library they wire into their own backend.
Hanko is a good option if you'd rather run authentication as its own service instead of embedding an auth library into your application code.
FAQ
Is there a free, open-source alternative to Better Auth?
Yes. Hanko is open source (AGPL-3.0) and free to self-host.
What's the best open-source alternative to Better Auth?
Hanko is the better pick if you want authentication running as a separate, passkey-first service rather than a library embedded in your own backend code.
What are the top open-source alternatives to Better Auth?
Browse all open-source alternatives to Better Auth above, or explore the full Security category for more options.