The open-source Auth0 alternative.
We build your sign in page so you don't have to.
AuthN, authZ, and user management in just 5 minutes.
Beautiful Next.js integration
We pride ourselves with our lean and responsive design. Your users will love it, and your developers too.
Features
Password, SSO, 2FA, and more
Beautifully styled components to help you get started quickly. No need to worry about design and internal logic.
Headless or headful UI
Integrate our shadcn/ui components, or build your own with our headless SDK.
JWTs without the JWTs
Stack manages JWTs and access tokens for you, so you get the performance benefits without ever having to think about them.
Organizations & teams
Manage B2B customers with orgs & teams, supporting email invitations, team components, and management tools.
3rd-party OAuth
Access third-party OAuth APIs such as Gmail or OneDrive without having to think about OAuth flows or token refreshes.
New features every week
We build and ship quickly. Subscribe to our newsletter or read our changelog to get the latest updates.
Here's how we compare
Among its competitors, Stack Auth is unique by being open-source, developer-friendly, and feature-rich.
vs. Auth0
Stack is open-source
Stack is for developers
Stack has reasonable pricing
Simple plans for everyone
Self-hosting is always free.
Everything you need to know
Can I integrate Stack into my existing project?
Yes! It is very straightforward! Stack does not require any special architecture and can merge well into any Next.js project that uses the App router.
How do I sync user data with my database?
For most of the time, you don't need to sync user data with your database. You can store JSON data in the user object itself. However, if you really need to sync data, you can use our webhooks.
Can I deploy Stack on my own servers?
Yes! Stack is fully open-source and you can self-host it on your own servers.
How can I integrate Stack into my backend?
Stack provides a Next.js server side SDK that you can just import and use. If you are using a different language or framework, you can use our REST API.
Does Stack support SSO with SAML?
Yes! Let's get in touch and we can help you.
What kind of support do you offer?
We offer a range of support from data migration to custom on-premise deployments.
Start building with Stack today
Secure your application with the best open-source authentication and user management platform.