Better Auth
Framework-agnostic authentication and authorization for TypeScript, run in your own app against your own database
Better Auth is an open-source, framework-agnostic authentication and authorization framework for TypeScript — sign-up, sign-in, and sessions in the core, with the harder pieces like two-factor, passkeys, single sign-on, and multi-tenancy added as plugins instead of hand-rolled. It has 29,198 stars on GitHub as of July 2026, is MIT-licensed, and keeps user records in your own database through adapters for Drizzle, Prisma, Kysely, and MongoDB. For a founder it removes weeks of undifferentiated work at the exact point a visitor becomes a user. What it does not touch is how many people reach your sign-in page in the first place — that is a separate job, and usually the harder one.
What Better Auth is
Better Auth (github.com/better-auth/better-auth) is an authentication and authorization framework for TypeScript that ties you neither to a particular web framework nor to a hosted identity vendor. You run it inside your own application, against your own database, and it handles sign-up, sign-in, sessions, and account management. It is MIT-licensed, written in TypeScript, and has been in active development since May 2024.
The project's stated reason for existing is that authentication in the TypeScript ecosystem is only half-solved: most open-source libraries cover basic login and then leave you writing a lot of code for anything beyond it, while the usual alternative is handing identity to a third-party service. Its answer is a comprehensive core plus a plugin ecosystem, so the advanced pieces are opt-in rather than rebuilt from scratch each time.
What it actually ships
The core covers the everyday path. The more interesting part is how much of the work you would normally defer is already packaged — these ship as first-party plugins and adapters in the repository:
- Your database, your choice — adapters for Drizzle, Prisma, Kysely, and MongoDB, so user records live in the database you already run instead of a vendor's.
- The security work you postpone — passkeys, two-factor, and single sign-on are plugins rather than a rewrite you schedule for next quarter.
- B2B plumbing — SSO and SCIM provisioning are in the box, which is normally the moment a small team starts paying an identity vendor in earnest.
- Past the web app — packages for Expo and Electron, plus i18n, so the same auth follows you to mobile and desktop.
- The adjacent pieces — an API-key plugin, an OAuth-provider package, and a Stripe integration for tying subscriptions to accounts.
Auth is the boundary — but rarely the bottleneck
Sign-in sits exactly on the line where a visitor becomes a user, which makes it tempting to treat as a growth lever. It is worth doing well: a slow, confusing, or untrustworthy sign-up does lose people at the moment they had already decided to try you. But the ceiling is low, because getting auth right removes a problem rather than creating demand.
- Does: whether signing up is fast, safe, and something you own rather than rent.
- Doesn't: how many of the right people arrive at your sign-in page at all.
- Doesn't: whether the people who do sign up ever reach the point where the product is useful to them.
We have first-hand data on that split. AgentCeres runs passwordless sign-in with magic links and Google OAuth, and when we instrumented our own funnel the surprise was where people were actually lost: almost none of the drop-off sat at the login screen. It sat after the account existed and before the product had done anything useful — so the work went into onboarding, not authentication. Better Auth removes weeks of effort at the boundary; the two harder jobs sit on either side of it — getting the right people there, and making the first session worth it. AgentCeres — the AI Growth Officer at agentceres.com — works on the first: a managed AI marketing team whose specialists draft the SEO, social, and outreach that bring people to a product, with a human approving anything that goes out.
FAQ
- Is Better Auth free?
- Yes. Better Auth is open source under the MIT license, which is about as permissive as software licenses get: you can use it commercially, modify it, and ship it without owing anything back. There is no hosted tier to buy, because you run it inside your own application — your costs are the database and servers you already pay for. Check the repository and better-auth.com for the current documentation and plugin list.
- Is Better Auth an alternative to Auth0 or Clerk?
- It solves the same problem from the other direction. Hosted identity services run auth for you, store the users, and price as you grow. Better Auth is a library you operate yourself, so user data stays in your database and there is no per-user bill — in exchange you own the deployment, the upgrades, and the security posture. Which trade is right depends on whether you would rather rent identity or run it, and how much a growing user table would cost you on a hosted plan.
- Does authentication affect conversion?
- Some, and it is worth not being the reason someone leaves — a clumsy or untrustworthy sign-up loses people at the worst possible moment. But the effect has a ceiling. Fixing auth recovers a slice of the visitors who already wanted in; it does not change how many of them show up. If signups are flat, the cause is almost always upstream of the login form, not inside it.
You built it. Now grow it.
AgentCeres is a managed AI marketing team — specialists draft the SEO, social, and outreach that fill your links, you approve what ships. 14-day free trial, from $19/month.