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Auth and identity

Auth0 vs Keycloak

Auth0 is a hosted identity service with 25,000 free MAU and tiered paid plans; Keycloak is a free, Apache-licensed identity server with no user limits that you run and patch yourself.

§1

The short answer

The trade is money against operations. Auth0 runs everything for you: free up to 25,000 MAU, then fixed MAU tiers such as B2C Essentials at $35 for 500 MAU and $700 at 10,000, or B2B Essentials from $150. Keycloak has no paid plans and no user limits; you pay only for the servers and database it runs on, and you handle upgrades, themes and clustering.

Protocol coverage overlaps: both handle OIDC, SAML, social login and enterprise connections. Keycloak adds built-in LDAP and Active Directory federation and fine-grained authorization, and suits internal SSO across many company applications. Auth0 adds 30+ SDKs, Actions and Forms for custom flows, attack protection and a Token Vault for AI agents.

On data location, Auth0 lets you pick a tenant region such as the EU, UK or Japan, and offers self-hosting only as a private deployment add-on on Enterprise. Keycloak runs wherever you put it, but the project itself offers no hosted service or paid support.

Choose Auth0 if

  • You do not want to run or patch an identity server
  • You sell to enterprises that need SSO, SCIM and compliance reports
  • You are building AI agents that call third-party APIs for users

Choose Keycloak if

  • You have many users and want no per-MAU fees
  • You need LDAP or Active Directory federation for internal SSO
  • You must keep identity data on your own servers
§2

Side by side

Auth0 Keycloak
Stages HobbyIndieStartupScale-upEnterprise HobbyIndieStartupScale-upEnterprise
What it is Hosted customer identity (CIAM) Open-source identity server
From From $35/mo (B2C Essentials, 500 MAU) Open source
Free tier Up to 25,000 MAU, unlimited social connections, passwordless, 5 organizations, 1 custom domain, 1 enterprise connection, self-service SSO and SCIM; community support only Entirely free and open source (Apache 2.0) with no user limits; you provide the servers and database
Free MAU 25,000 MAU Unlimited (self-hosted)
After free B2C from $35/mo for 500 MAU; B2B from $150/mo Free; you pay only for hosting
Enterprise SSO 1 connection free; 3 on B2B Essentials; extra $100/mo each SAML 2.0 and OIDC, free
Self-host No (private cloud on Enterprise) Yes (Apache 2.0)
Open source No Yes
Self-hostable No Yes
EU data residency Available Available
Compliance ISO 27001, ISO 27017, ISO 27018, CSA STAR Level 2 Not stated
Checked 28 Sept 2026 28 Sept 2026
Strengths
  • Free plan covers 25,000 MAU and includes an enterprise SSO connection and SCIM
  • Very broad protocol, SDK and enterprise feature coverage
  • Tenant regions include the EU and UK
  • ISO 27001/27017/27018 and CSA STAR reports available through the Okta trust center
  • Free and Apache-licensed with no user limits
  • Covers OIDC, OAuth 2.0, SAML, LDAP and AD in one server
  • Large, long-running community (since 2013)
  • Runs anywhere, so data location is your choice
Limitations
  • Paid pricing climbs steeply: B2C Essentials is $700/mo at 10,000 MAU
  • B2B plans start at $150/mo for 500 MAU
  • Prices only at fixed MAU tiers; between tiers you pay the next tier
  • Custom database connections and enhanced attack protection require Professional
  • You must operate, upgrade and scale the Java server and its database
  • No official hosted service or paid support from the project itself
  • Custom login UI means working with Keycloak themes
  • Heavier to set up than developer-first hosted auth for a single app

Sources: Auth0 pricing, Keycloak pricing. Full plans on each tool's page.

§3

Plans

Auth0

Free
25,000 MAU, 5 organizations, 1 enterprise connection, SCIM		 Free
B2C Essentials
500 MAU; $70 at 1,000, $700 at 10,000, $3,500 at 50,000 MAU		 $35/mo
B2C Professional
Up to 1,000 MAU; $1,600 at 10,000 MAU; enhanced attack protection, custom DB		 $240/mo
B2B Essentials
500 MAU; unlimited organizations, 3 enterprise SSO connections, RBAC		 $150/mo
B2B Professional
Up to 1,000 MAU; enterprise MFA, custom token exchange, more connections		 $800/mo
Enterprise
99.99% SLA, enterprise rate limits, private deployment add-on		 Custom

Keycloak

Keycloak
Self-hosted, Apache 2.0, all features		 Free

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