Auth0 vs Keycloak
A source-aware comparison of pricing, documented capabilities and workflow fit.
Short answer
- Price: not directly comparable — Auth0 is free tier available, Keycloak is free.
- How to start: Auth0 is free tier available, Keycloak is free.
- Where they differ: only Keycloak has open source / self-hostable; both offer public api and sso (saml).
These lines are generated from the pricing we track, not from a paid placement. How we score tools.
What Auth0 is
What Auth0 isAuth0 is a mature identity platform covering login, social providers, enterprise SSO and fine-grained authorisation, now part of Okta. It covers the awkward parts most teams underestimate: enterprise SSO connections, MFA policy and tenant-level rules. The cost profile is the usual objection, since monthly active users climb faster than expected once consumer signup is open.
What Keycloak is
What Keycloak isKeycloak is open-source identity and access management supporting OIDC and SAML, run on your own infrastructure. Running it yourself means user data and session policy stay inside your infrastructure, which is often the deciding factor in regulated environments. The price is that authentication becomes something your team operates, upgrades and keeps available.
Side by side
| Auth0 | Keycloak | |
|---|---|---|
| Category | Developer Tools | Developer Tools |
| How to start | Free tiernot a monthly price | Freeverified |
| Public API | Yes | Yes |
| Mobile app | No | No |
| Open source / self-hostable | No | Yes |
| SSO (SAML) | Yes | Yes |
| Visit | Auth0 ↗ | Keycloak ↗ |
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What Auth0 is built to do
- Social and enterprise connections
- Federates logins from social providers and customer SAML or OIDC identity providers.
- Rules and actions
- Runs custom logic during login to shape tokens and enforce policy.
- MFA and anomaly detection
- Adds step-up factors and blocks credential-stuffing attempts.
What Keycloak is built to do
- OIDC and SAML
- Acts as an identity provider for both protocols and brokers external ones.
- Realms and roles
- Separates tenants into realms with their own users, clients and role mappings.
- Self-hosted
- Runs on your own infrastructure so credentials never leave it.
Choose Auth0 if
- Apps under 25,000 monthly active users — the Free plan includes a custom domain, passwordless and 5 organisations
- Consumer apps that outgrow Free: B2C Essentials starts at $35/month for 500 MAUs
- B2B SaaS that needs enterprise connections and unlimited organisations: B2B Essentials from $150/month
Skip Auth0 if
- You need B2B features on a small budget — B2B plans cost roughly four times the B2C plans at the same MAU
- Your MAU count is large: paid plans are priced per MAU tier from 500 upward
- You need compliance and SLAs: Enterprise is quoted by sales
Choose Keycloak if
- Teams that want a free, Apache-licensed identity server with OpenID Connect, OAuth 2.0 and SAML 2.0
- Organisations that must keep identity data on their own infrastructure
- Companies that want a CNCF project rather than a per-MAU SaaS bill
Skip Keycloak if
- You have nobody to run and upgrade it: Keycloak is self-hosted and the operational cost is yours
- You need vendor support without a Red Hat subscription
- You want a managed service with a free tier and no servers — Auth0 or Clerk fit that better
Evidence and freshness
Where a claim on this page comes from a vendor page, it is linked here.
Keycloak
Open source, free — vendor page verified · reviewed 2026-09-08
Auth0: pros & cons
- Handles enterprise SSO requirements that block deals
- Extensive protocol and standards support
- Well documented and widely known
- Expensive as active users grow
- Configuration surface is large
- Migration away is difficult once embedded
Keycloak: pros & cons
- Full identity server at no licence cost
- Standards support including SAML and OIDC
- Complete control over user data
- Operating it is a real responsibility
- Administration console is dense
- Upgrades need care
Our verdict on Auth0
The safe answer for enterprise identity. For a consumer app with simple needs it is more platform than you need.
Our verdict on Keycloak
The serious open-source answer to Auth0. Budget for the operations, because the licence saving is not free.
Published plans, side by side
Every figure below was read from the vendor's own pricing page and is shown with the sentence it came from. Where a vendor publishes no plan prices, we say so rather than guess.
Auth0
- Free$0/mo
Free: up to 25,000 MAUs, 1 custom domain, passwordless, unlimited social connections, 5 organisations, 1 enterprise connection
- Essentials$35/mo
Essentials from $35/month (B2C) or $150/month (B2B) at 500 MAUs
- Professional$240/mo
Professional from $240/month (B2C) or $800/month (B2B) at 500 MAUs
Keycloak
No published plan prices verified. Keycloak either quotes on request or renders its prices in a way we could not read from the pricing page.
Auth0 vs Keycloak: common questions
- Does Auth0 or Keycloak have a free plan?
- Both do: Auth0 has a free tier with limits, and Keycloak is free.
- What is the difference between Auth0 and Keycloak?
- On the criteria we check, only Keycloak has open source / self-hostable; both offer public api and sso (saml). The table above lists every criterion side by side.