Stack Auth (YC S24) is the open-source Auth0 alternative. We build your login and signup pages, and everything that comes with that.

We are the most developer-friendly auth solution. Setting up Stack takes just five minutes; after that, you will immediately be able to use our features such as two-factor authentication, social logins/OAuth, magic links & passwords, authorization, RBAC, user management, impersonation, webhooks, and more.

Our JavaScript packages include ready-to-use React components that let you skip building the frontend pages for account settings, forgot-password flows, and user dashboards. Thanks to this, we have thousands of GitHub stars, and are growing incredibly quickly.

Konsti and Zai met while studying computer science at ETH Zurich and incubated this project at SPH. We are repeat founders with work experience at Google and Jane Street, and published papers at top conferences.

We are also hiring — if you're passionate about the future of devtools and the web, we should talk. Send us your CV team@stack-auth.com