Auth0

The enterprise identity platform — flexible authentication and authorization for any app, any stack.

What is Auth0?

Auth0 (by Okta) is the most established name in developer identity: a platform handling authentication, authorization, SSO, MFA, and user management across effectively every language, framework, and protocol. Universal Login centralizes flows with deep customization through Actions (serverless hooks at every lifecycle point); enterprise federation (SAML, OIDC, AD/LDAP), organizations for B2B, fine-grained authorization, and bot/attack protection cover requirements that smaller rivals reach years later. That breadth is the pitch: whatever your auth requirement becomes — consumer apps, B2B SaaS, machine-to-machine, IoT — Auth0 already has the primitive. The free tier now covers 25,000 monthly active users, making it genuinely viable for startups, while pricing at scale (and per-feature gating) remains the chief complaint that sends cost-sensitive teams to alternatives. For enterprise-grade requirements with compliance attached, it's still the safe answer.

Key Features

Universal Login with customizable hosted flows

Enterprise federation: SAML, OIDC, Active Directory, LDAP

Actions: serverless hooks customizing every auth event

Adaptive MFA, bot detection, and breached-password protection

Organizations and fine-grained authorization for B2B

Use Cases

Enterprise SSO across internal and customer-facing apps
B2B SaaS onboarding customers' identity providers
Consumer apps needing social login plus MFA at scale
Machine-to-machine API authorization

How to Use Auth0

1Create a tenant and register your application
2Integrate an SDK or redirect to Universal Login
3Configure connections: social, database, enterprise IdPs
4Extend flows with Actions and enable MFA policies

Best For

Enterprises with compliance and federation requirementsTeams on stacks outside the React ecosystemProducts that will grow into complex auth needs

FAQ

Is Auth0 free?

The free plan covers up to 25,000 monthly active users with core authentication. Paid plans start around $35/month, with enterprise features priced significantly higher.

What are Auth0 Actions?

Actions are serverless functions that run at points in the auth pipeline — post-login, pre-registration, etc. — letting you enrich tokens, enforce rules, or call external systems without running servers.

When is Auth0 the wrong choice?

Early-stage React products optimizing for speed often prefer Clerk's components, and cost-sensitive high-MAU consumer apps frequently choose open-source or usage-friendlier options.

Looking for Auth0 alternatives?

Compare 3 hand-picked alternatives by pricing, free plans, and open-source availability.

View Alternatives

Compare Auth0 side by side

In-depth, editor-written comparisons with a clear verdict.

Auth0 vs Clerk

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