# auth0

Source: https://startwithidentity.com/vendors/ciam/auth0/
Last updated: 2026-01-15
License: content by Start with Identity. Cite the source URL.

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## Overview

Auth0 launched in 2013 as a developer-first identity service and was acquired by Okta in 2021, where it remains the customer-identity ([CIAM](https://startwithidentity.com/guides/fundamentals/what-is-ciam/)) product, distinct from Okta's workforce platform. It is the reference platform for engineering teams that want to add login to an app quickly and customize deeply, and it carries the largest mindshare in the category.

## What it is good at

Developer experience is the moat: excellent SDKs and quickstarts across every major language and framework, thorough documentation, and broad protocol coverage (OIDC, SAML, OAuth, WebAuthn/passkeys). Actions, its serverless extensibility model, lets teams customize login flows in code without forking the platform. It handles both B2C and B2B (organizations, enterprise connections), supports MFA and passwordless well, and offers a dedicated private cloud for stricter requirements. Note that [Auth0 Private Cloud](https://auth0.com/docs/deploy-monitor/deploy-private-cloud) is a managed service on AWS or Azure, single-tenant and isolated but run by Auth0, not software you host yourself.

## Where it falls short

Per-MAU economics are the recurring complaint: pricing climbs steeply with scale, B2B and enterprise features sit in higher tiers, and list price is rarely what large customers pay, so plan to negotiate. Governance and lifecycle are lighter than a dedicated workforce or [IGA](https://startwithidentity.com/vendors/iga/) tool, since that is not its job. Some buyers also weigh the Okta ownership and the platform's history of security incidents, which makes tenant hardening a real task.

## Pricing

Free tier for small projects, then per-monthly-active-user tiers that escalate, with B2B, advanced MFA, and enterprise capabilities gated to higher plans. Model costs at your real MAU and feature set with the [TCO calculator](https://startwithidentity.com/tools/tco-calculator/).

## Best for, and who should look elsewhere

Choose Auth0 when developer experience and protocol breadth drive the decision and you want one platform for B2C and B2B. For B2B-only enterprise readiness consider [WorkOS](https://startwithidentity.com/vendors/ciam/workos/); for the lowest cost and self-hosting consider open-source options like [Keycloak](https://startwithidentity.com/vendors/open-source/keycloak/); for the best React drop-in UX consider [Clerk](https://startwithidentity.com/vendors/ciam/clerk/).

## Bottom line

The developer-favorite CIAM with the deepest SDK and protocol coverage. Watch the per-MAU bill as you scale.