Auth.js

Open-source authentication for the web (formerly NextAuth.js), free and framework-native.

EstablishedOpen SourceLow lock-in
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Pricing

Free tier

Flat rate

Adoption

→Stable

License

Open Source

Data freshness

Verified · Jul 12, 2026

Overview

What is Auth.js?

Auth.js (NextAuth.js) is the de facto open-source auth library for Next.js and other JS frameworks — OAuth, email, and credentials with your own database.

Key differentiator

“The free, open-source default auth for Next.js.”

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Free and open sourcehigh

No per-user fees; runs entirely in your app

First-class Next.js integrationhigh

The default auth choice for the Next.js ecosystem

Many OAuth providers built inmedium

Dozens of prebuilt provider configs

↓ Weaknesses

You build the UI and manage the DBmedium

No hosted UI or user dashboard like Clerk

Enterprise SSO needs extra workmedium

SAML/SCIM not first-class

Fit analysis

Who is it for?

✓ Best for

Next.js apps wanting free, self-hosted auth

Native integration, no per-user cost

Developers comfortable owning auth plumbing

Full control over sessions and providers

Cost structure

Pricing

Free Tier

Available

Fully free and open source

Starts at

$0

Model

Flat rate

Enterprise

None

Performance benchmarks

How Fast Is It?

Ecosystem

Relationships

Next step

Get Started with Auth.js

Step-by-step setup guide with code examples and common gotchas.

View Setup Guide →