Better Auth vs Keycloak

Better Auth is an open-source authentication and authorization library for TypeScript, distributed under the MIT license. Instead of sending users to a hosted identity service, it runs inside your own backend and stores users, sessions and accounts in your own database through adapters for Drizzle, Prisma, Kysely, MongoDB and plain SQL drivers. It is framework-agnostic, with integrations for Next.js, Nuxt, SvelteKit, Astro, Hono, Express and others, and typed clients for React, Vue, Svelte, Solid and vanilla JavaScript.

The core covers email and password, social OAuth providers and session management; a plugin system adds two-factor authentication, passkeys, magic links, email OTP, username login, organizations with teams and roles, admin tools, multi-session, API keys, JWT, an OIDC provider and more. A CLI generates the schema and migrations each plugin needs. The library is free with no per-user pricing; an optional managed service (free Starter, $20/month Pro) adds a dashboard.

Better Auth suits TypeScript teams that want control over user data and login flows without writing auth from scratch. The trade-off is responsibility: you handle hosting, security updates and email delivery, and the core ships no prebuilt UI components. Clerk and Auth0 provide hosted UI, dashboards and enterprise SSO for a per-user fee; Supabase Auth is convenient if you already use Supabase; Auth.js (NextAuth) is the older open-source option with fewer built-in features.

The project grew quickly in 2024 and 2025 as Lucia was deprecated.

Keycloak is an open-source identity and access management server, originally created by Red Hat and now a Cloud Native Computing Foundation (CNCF) incubating project under the Apache 2.0 license. It provides single sign-on for web and mobile applications and APIs using the standard OpenID Connect, OAuth 2.0 and SAML 2.0 protocols, and it runs on your own infrastructure.

Its feature set matches commercial identity products: user federation with LDAP and Active Directory, identity brokering with social logins and external identity providers, multi-factor authentication with OTP and WebAuthn, password policies, fine-grained authorization services, realms for multi-tenancy, an admin console and a self-service account console. Login pages and emails can be themed, and extensions are written in Java through service provider interfaces. The software is free; Red Hat sells a supported distribution, the Red Hat build of Keycloak, for organizations that need commercial support.

Keycloak fits enterprises, public institutions and B2B software vendors that need to keep identity data under their own control, for example for data residency or regulatory reasons. The trade-off is operational: running it in high availability, tuning databases and caches, upgrading between major versions and customizing themes require expertise. Startups that want hosted authentication with polished UI components usually choose Auth0, Clerk or WorkOS, while Authentik and Zitadel are newer open-source alternatives with lighter operations.