Supabase Auth vs Clerk vs Better Auth
Choose authentication for a Next.js app by comparing ownership, integration, operations, and authorization.
Choose Supabase Auth when your application already uses Supabase and its identity and database integration fits your needs. Choose Clerk when a managed identity service with ready-made interface components is valuable to your team. Consider Better Auth when you want a TypeScript authentication framework running with your application and are prepared to operate its data and configuration. All three can support a Next.js app; none removes your responsibility to authorize access to your product's data.
This comparison uses the providers' documentation checked on October 30, 2026. Check current features, pricing and terms for your actual use before choosing.
What changes with each choice?
| Decision | Supabase Auth | Clerk | Better Auth |
|---|---|---|---|
| Main integration | Auth service in a Supabase project, with client libraries and database integration. | Managed identity service with a Next.js SDK, components and server helpers. | TypeScript framework configured in your application, with database adapters and plugins. |
| Useful starting point | You already use Supabase Postgres and want its Auth and row-level security to work together. | You want hosted identity features and prebuilt sign-in UI. | You want application-owned configuration and control over your auth stack. |
| Work you still own | Session integration, database policies, authorization, provider configuration and operations appropriate to your deployment. | App authorization, integration and provider settings, including any data synchronization you need. | Database and deployment, configuration, migrations, email delivery and application authorization. |
See the Supabase Auth overview, Clerk Next.js SDK, and Better Auth introduction for their actual supported flows. Better Auth's plugins and Clerk's prebuilt components solve different parts of the work; availability or configuration of a feature is not proof it is correctly enabled in your app.
Start with the user journey
List the flows your first customers need: email and password, Google sign-in, password recovery, invitations, or multiple organizations. Then check the provider's current documentation for each flow, including account linking and recovery. Try a complete sign-in, a server-rendered private page and a protected write before committing to an architecture.
With Supabase SSR, browser and server clients share a cookie-backed session, and a request boundary refreshes tokens. The Supabase SSR guide explains the setup. Clerk supplies server-side helpers and UI components. Better Auth exposes its configured authentication service through your app; its Next.js integration guide explains the handler and session integration.
A sign-in screen proves identity can be established. It does not prove that a user can only read their own projects. For every sensitive request, verify the identity on the server, load the relevant membership or ownership, and reject unauthorized reads and writes. If you use Supabase row-level security, test the actual policies and avoid using a privileged key as a substitute for user authorization.
Data and organization boundaries
Supabase Auth users belong to the Supabase project and integrate with its Postgres and row-level security; you still model your application's organizations and membership policies. Supabase's RLS guide explains enforcement. Clerk manages identity and provides organizations, invitations and roles; your application must enforce access to its own data using the right organization context. Better Auth runs in your application with its configured database adapter; its organization plugin adds members, teams and permissions after configuration and schema migration. None automatically secures every application query.
Compare the operating cost, not just the free tier
As of October 30, 2026, Supabase lists a free plan with 50,000 monthly active users and Pro from $25 per month with 100,000 included, then $0.00325 per additional monthly active user. Database, compute and other usage have their own limits and charges. Clerk lists free Hobby with a 50,000 monthly retained user limit per app; Pro is shown at $20 per month billed annually, with 50,000 included and published overage rates. Its included organization tier lists 100 monthly retained organizations and up to 20 members each. Monthly retained users are defined differently from Supabase's monthly active users, so those counts are not interchangeable.
Better Auth is open source; budget for the database, hosting, email and your own operation rather than assuming those costs are zero. Estimate the actual users, required features and organization sizes for your app, then recheck each provider's current plan, billing terms and eligibility. Prices and quotas can change.
Before switching an existing product, inventory user IDs, linked identities, password recovery, sessions, organization membership, and any database policies tied to the old identity. Plan a migration and test it with representative accounts. Changing the login form alone does not migrate those relationships.
A practical default
If you are already building on Supabase, start by implementing its documented cookie and server verification path. How to add authentication to Next.js walks through the boundaries and reject cases. If managed UI and identity operations are your priority, evaluate Clerk's SDK against the same cases. If control of the auth implementation is the priority, evaluate Better Auth and budget for its deployment and maintenance.
CoreMVP's sold Next.js template uses Supabase Auth with server-side session management, email and password, magic links and a Google sign-in control. Its OAuth handler accepts GitHub, but using GitHub requires enabling the provider and adding controls to both sign-in and sign-up forms. Its authentication documentation describes the shipped path. That foundation can save the work of connecting these pieces, while your application still owns its authorization rules.