Auth.js vs Better Auth
Two library in your app options for authentication. When each fits, what it costs, who moves from one to the other, and what makers who chose it say.
Which fits you
Choose Auth.js if- Existing Next.js apps built on NextAuth, and teams that want OAuth sign-in with users in their own database.
Use it whenYour app already uses NextAuth or Auth.js and works; you're maintaining it rather than choosing fresh.
Trade-offThe project is now part of Better Auth, which offers a migration guide; v5 has stayed in beta for a long time, and features like two-factor or organizations are yours to build.
Choose Better Auth if- You want users in your own database and no per-user bill
Use it whenYou'd rather own the code than pay per user.
Trade-offYou host it and keep it patched; UI is yours to build.
At a glance
| Auth.js | Better Auth | |
|---|---|---|
| Used by | No maker's product yet · 57 open-source projects | 6 makers' products · 94 open-source projects |
| Cost at default usagemonthly active users 10k MAU | — | $0/mo Self-hosted (open source) |
| Downloads | 5.7M/wk−6% vs npm | 6.5M/wk8.4× vs npm |
| Pricing | Free (open source). | Free (open source). |
| Free tier | Yes | Yes |
| Open source | Yes · self-hostable | Yes · self-hostable |
Cost as you grow
Both are $0 at every scale we price, up to 1M MAU — what you pay for is the servers you run them on.
The numbers, plan by plan
| Monthly active users | Auth.js | Better Auth |
|---|---|---|
| 100 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
| 1,000 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
| 5,000 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
| 10,000 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
| 25,000 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
| 50,000 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
| 100,000 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
| 250,000 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
| 1,000,000 | $0 Self-hosted (open source) | $0 Self-hosted (open source) |
From each vendor's pricing page: Auth.js, Better Auth.
What makers say
Makers on using it for authentication, from Product Hunt and Starter Story interviews, each linked to the source. Products with a page of their own and fuller notes first.
On Auth.jsNo maker quote about Auth.js for authentication yet.
On Better AuthAuthentication is always a time sink, but not with better_auth. Simple, secure, and extendable. Got magic links and login flow done in under an hour.
Better-Auth gave us a clean, flexible auth layer with minimal code. Performance, adaptability, and dev-experience were all wins.
It came out of nowhere and became popular for a good reason - it's really good!
Loved and watch-outs
Themes that recur in makers' words and Hacker News comments, each linked to what it summarises.
Auth.jsNothing that recurs in what we collected yet.Better Auth- A library that keeps users and sessions in your own database, with no vendor dependency and no per-user fees. HNHN 2HN 3HN 4
- Plugins cover OAuth providers, magic links, RBAC, SSO and SAML, going well beyond Auth.js. HNHN 2HN 3PH
- Hackable and transparent, so custom flows such as iframe login work without fighting hidden internals. HNHN 2PH
- Built-in assumptions force hacks, such as OIDC providers without email or request-header-based admin scripts. HNHN 2
- Code quality felt rushed, with few tests and little logging, and audit logs need the managed service. HNHN 2
- Breaking changes appear in patch releases, and the OpenAPI spec gets little care for non-JS clients. HN
Who uses each
Clarm
PicMotionAI
Prism AIWhat makers pair each with
With Auth.js
papermarksourcebottambotextbeeanalyzemyrepoand 43 more
Bun
Langfusepapermarksourcebotanalyzemyrepoasrvd.me
Cal.comcal.diychirpyand 17 more
create-t3-app
OpenStatus
DubWith Better Auth
inbox-zeroand 77 moreinbox-zero
Latitudeand 59 more
superset
BlockNote
Helicone
Mastra
RybbitarchestraCallDatabuddydeepcrawldoryelmoLatitudenelsonlai.devpaperclipscirasuperlogand 46 more
Dokploy
NovuNeither quite right?
See the whole authentication decision →
ClerkHosted serviceDropping prebuilt sign-in, profile and organization UI into a React or Next.js app.vs Better Auth →
SupabaseBundled with your backendApps already on Supabase — auth is part of the same project as the database.vs Better Auth →
FirebaseBundled with your backendMobile and client-heavy apps already using Firebase.
WorkOS
Auth0