How it works
Auth0 usually shows a hosted Universal Login page on its own domain or yours, so passwords never touch your app. It supports passwords, passwordless email and SMS, passkeys, social providers, MFA, and enterprise connections to SAML, Microsoft Entra ID, Google Workspace and LDAP directories. Apps connect through OpenID Connect and OAuth 2.0 with SDKs for most languages, and Actions (small Node.js functions) customise what happens during sign-up and sign-in.
Its strength is the business end: organisations for B2B customers, each with its own SSO connection and branding, role-based access control, protection against bots and credential stuffing, audit log streaming, and the certifications enterprise security reviews ask for. Okta bought the company in 2021, and it also sells Fine-Grained Authorization, based on Google's Zanzibar model, and identity tools for AI agents.
The trade-offs are cost and complexity. The free plan is generous, but paid plans start with a few hundred included users and rise with each step up in monthly active users, and features such as enterprise MFA or connecting your own user database sit on higher tiers. Configuration spans many dashboard screens, and leaving later means rebuilding rules and connections elsewhere.
Auth0 pros and cons
Pros
- Broad feature set: social, passwordless, passkeys, MFA and enterprise SSO
- Hosted login page keeps passwords out of your app
- Strong B2B tools: organisations, per-customer SSO and SCIM
- Compliance certifications that help pass enterprise security reviews
- Free plan covers up to 25,000 monthly active users
Cons
- Paid plans get expensive as monthly active users grow
- Many settings and concepts to learn
- Advanced features are spread across higher, pricier tiers
- Actions, rules and connections take effort to move elsewhere
When to use Auth0
Pick it when
- B2B software whose customers ask for SAML SSO and directory sync
- Regulated or enterprise settings that need certifications and SLAs
- Many apps and APIs that share one identity system
Skip it when
- A small consumer app where per-user costs could outgrow revenue
- You already use Supabase or Firebase, whose built-in auth covers the basics
Auth0 pricing
Free tier
Free for up to 25,000 monthly active users. Paid plans start with Essentials from about $35 a month for 500 users, and Professional from about $240 a month; prices rise with user count.
Auth0 pricing page (opens in a new tab)Approximate, checked September 2026.What the other tools cost
Auth0 vs the alternatives
Related terms
More in Auth and identity
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