Auth0 review

Auth0 is an identity platform for managing who can sign in to websites, apps and APIs, and what they can access. Its product materials cover customer sign-up and login, enterprise identity, fraud prevention and machine identity security. In practice, that spans passwordless and social login, embedded login, adaptive MFA, bot detection, enterprise SSO and SCIM.

Auth0 also covers authorization and service-to-service access. Teams can set permissions for users and AI agents, control access to RAG data, and authenticate services or APIs with Client Credentials and short-lived tokens. Its AI agent identity features are intended to give agents verifiable identities and govern access to data sources and MCP tools.

The point is a managed identity layer rather than a login screen alone: Auth0 handles authentication and access controls across different kinds of users and systems. How much of that you need matters, because the listed plans have different MAU caps, tenant limits and security features.

Auth0’s main strength is breadth. Its feature set covers customer authentication, enterprise connections and machine-to-machine access in one identity platform, rather than limiting the product to basic email-and-password login.

• For customer apps, Auth0 lists passwordless login, social login and embedded login, alongside adaptive MFA and bot detection.
• For business customers, it supports enterprise SSO, SCIM and customer-managed organizations. A commenter on r/nextjs says enterprise buyers asked their company for SCIM, SAML, OIDC and audit logs; they used Auth0 on top of existing identity providers. That is one user’s account, not a guarantee that every deployment will pass a security review.
• For APIs and services, the feature list includes Client Credentials and short-lived tokens. Fine-grained authorization can cover users, agents and RAG data, while the AI agent identity features extend access control to data sources and MCP tools.

The free plan is listed at $0 per month and includes up to 25,000 monthly active users, one custom domain, five organizations, one enterprise connection and one tenant. That gives teams building and testing apps room to explore the platform, although the listed caps still matter if the app needs more domains, connections or tenants.

The plan table has a sharp and potentially confusing MAU split. Free lists up to 25,000 monthly active users, while Essentials is $35 per month and lists a cap of 500. Professional is $240 per month and also lists 500 MAU. The pricing page does not explain this apparent mismatch, so confirm which plan and usage model apply to your product before budgeting.

Other limits can constrain a production setup: Essentials lists 10 organizations, 1,000 M2M authentications, three tenants and five-day log retention. Professional lists 5,000 M2M authentications, 12 tenants, 10-day retention and two log streams. Enterprise pricing is not published; its listed inclusions are custom user and SSO tiers, unlimited tenants, 30-day log retention, a 99.99% SLA and two log streams.

Add-on prices are also not published, including Advanced Security Features, Private Deployment, Adaptive MFA and Bot Detection. The pricing page offers monthly and yearly billing toggles, but the published prices show monthly rates only. Reddit users report concerns about rising costs, including one thread citing a B2C Essentials per-MAU increase; that user-reported figure does not match the listed flat monthly plans. Get a current quote rather than treating the thread as a price sheet.

Auth0 lists a free plan, then monthly prices of $35 for Essentials and $240 for Professional. Enterprise pricing is custom, so the price is not published. Annual billing is available as a toggle on the pricing page, but the published pricing details show no annual rates. The page also lists a 22-day free trial.

Check the user caps before comparing tiers: Free includes up to 25,000 monthly active users, while Essentials and Professional each list up to 500. Professional costs $205 more per month than Essentials, with the same stated MAU cap; it adds more M2M authentications, tenants, log retention and two log streams. Essentials includes 1,000 M2M authentications; Professional includes 5,000.

Several extras can raise the bill, but prices are not published for M2M Tokens, Advanced Security Features, Private Deployment, Bot Detection, Adaptive MFA and other listed add-ons. Confirm which features your plan includes and get the full quote before committing.

Treat an Auth0 migration as an identity-system change, not just a login-widget swap. Auth0 covers customer authentication, enterprise connections, SSO, SCIM, organizations, permissions, machine authentication and AI agent identity. Map the parts you use, plus the applications and APIs that depend on them, before estimating the work. The published material does not specify migration tooling, user-data export formats or a standard migration path, so confirm those details with Auth0 before moving.

To reduce lock-in, document your login flows, connections, permissions and machine-to-machine credentials, and ask how each can be transferred or recreated elsewhere. Also price the features you rely on: several security and identity add-ons have no published rates, and Enterprise pricing is custom.

We can’t substantiate what tends to make users leave based on Reddit: no Reddit posts or comments were included in the published material. The clearest published reasons to scrutinize a switch are plan caps, unpublished add-on costs and the effort of replacing identity controls across apps and APIs.