Keycloak
Top pickThe mature, CNCF-backed open-source identity and access management server.
90
sovereigntyKeycloak is a full-featured IAM server originally built by Red Bull's security team and now a CNCF Incubating project. It supports OIDC, OAuth2, and SAML, social and enterprise identity brokering, fine-grained authorization, and a built-in admin console, and it's the most widely deployed self-hosted alternative to Auth0/Okta in production today.
OPEN SOURCEApache-2.0SELF-HOSTLOCAL-FIRST
LicenseApache-2.0
PricingFree / self-host (Docker image or standalone distribution); commercial support available via Red Hat build of Keycloak (RHBK) for enterprises that want a support contract.
Open sourceYes
Self-hostableYes
Local-first dataYes
What it does well
- +Apache-2.0, fully open-source, no feature gating between a 'community' and 'enterprise' edition
- +Extremely mature — 10+ years in production at large scale, CNCF Incubating project with active governance
- +Broad protocol support (OIDC, SAML, OAuth2) and identity brokering to external IdPs out of the box
- +Large ecosystem of themes, extensions, and Kubernetes operators for production deployment
Where it falls short
- −Runs on the JVM — heavier resource footprint than lightweight Go-based alternatives, and the admin console/config model has a real learning curve
- −You own uptime, patching, and database backups for something security-critical — a genuine operational responsibility Auth0 absorbs for you
- −Theming the login UI to match a product's brand takes more custom work than Auth0's Universal Login customization
Keycloak as an alternative to
Where Keycloak shows up in our comparisons, and how it ranked.
Keycloak head-to-head
Straight comparisons against the tools people weigh it against.