Top Free Alternatives to Auth0

Stop paying expensive subscriptions for Authentication tools. Discover the best free and open-source replacements for Auth0.

Why switch from Auth0?

Auth0's pricing jumps exponentially once you cross their free tier limits, especially for B2B applications requiring SAML or SSO. Open-source auth providers include SSO out of the box.

SuperTokens

Free / Cloud Paid
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Open source alternative to Auth0 / Firebase Auth / AWS Cognito.

Key Features

  • Session management
  • Social login
  • Passwordless
  • Multi-tenant SSO

Pros

  • + You own your user data
  • + Highly customizable frontend
  • + Excellent documentation

Cons

  • - Self-hosting requires maintaining a separate database for auth
  • - Less robust B2B directory sync than Auth0

Keycloak

Free / Open Source
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Open Source Identity and Access Management.

Key Features

  • Single-Sign On
  • Identity Brokering
  • User Federation
  • Standard Protocols

Pros

  • + Enterprise-grade security
  • + Supported by Red Hat
  • + Incredibly feature-rich

Cons

  • - Heavyweight Java application
  • - UI is complex and dated
  • - Hard to customize the login theme

BoxyHQ

Free / Open Source
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Enterprise Readiness made simple

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support

Cerbos

Free / Open Source
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Granular access control

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support

FusionAuth

Free / Open Source
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User authentication and session management framework

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support

Hanko

Free / Open Source
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Passkey-first authentication framework

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support

OPAL (Permit.io)

Free / Open Source
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Authorization administration framework (Open Policy)

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support

Ory

Free / Open Source
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Identity platform

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support

Oso

Free / Open Source
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Authorization building framework

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support

Warrant

Free / Open Source
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Authorization and access control as a service

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support

Zitadel

Free / Open Source
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User authentication and session management framework

Key Features

  • 100% data control
  • Self-hostable
  • No vendor lock-in
  • Community-driven

Pros

  • + Ownership of your data
  • + Flexible and customisable
  • + Cost-effective

Cons

  • - Requires server setup
  • - Smaller commercial support