Tools/supertokens/supertokens-core

SuperTokens

Open source alternative to Auth0/Firebase Auth/Cognito

15.3k ★+14/wkgrowthJavaApache License 2.0 →new this week

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Replaces:AWS Cognito Auth0 Clerk Stytch

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The Lens

By Erik Loyd, SaaS CEO and former COO/CFO of an AWS Premier Partner.

Updated Jul 2026

SuperTokens is the open source authentication platform: signup, password reset, social login, multi-factor auth, without Auth0 prices or Firebase lock-in. It handles session management, email verification, passwordless login, and social OAuth out of the box.

Self-hosting is free with all features. The managed cloud has a free tier up to 5,000 monthly active users (MAUs), which covers most startups. Paid tiers kick in at scale.

The catch: the self-hosted version requires running a Java-based core service alongside your app. That's a real dependency: Java runtime, separate process, separate database. The cloud version eliminates this but you're trusting a smaller company with your auth. And the SDK ecosystem, while growing, is narrower than Auth0's. Check that your framework is supported before committing.

Free vs Self-Hosted vs Paid

open core

Self-hosted (free): All features included: email/password, social login, passwordless, MFA, session management. Requires running the SuperTokens core (Java) with a PostgreSQL or MySQL database. No user limits.

Cloud free tier: Up to 5,000 MAUs. All auth features included. No credit card required.

Cloud paid: $0.02/MAU beyond 5,000. So 10,000 MAUs = $100/mo. 50,000 MAUs = $900/mo.

Compared to Auth0: Auth0's free tier is 7,500 MAUs but with significant feature restrictions. At 10,000 MAUs, Auth0's Essentials plan is $240/mo. SuperTokens is $100/mo, less than half.

When to pay: If you don't want to run Java in production. The cloud version is meaningfully cheaper than Auth0 at every tier.

Self-host free. Cloud free up to 5K MAUs, then $0.02/MAU, roughly half of Auth0's pricing.

What to do by team size

Solo: Cloud free tier handles 5K users. Don't self-host unless you enjoy running Java services.
Small team: Cloud free tier probably covers you. Self-host if you need full data control.
Medium team: Self-host to save money at scale, or cloud at $0.02/MAU if ops time is expensive.
Large team: Self-host for compliance and cost. At 100K MAUs, cloud would be $1,900/mo vs free + infrastructure.

Self-hosting ops:moderate

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