Keycloak

What is it

Keycloak is an open-source identity and access management solution aimed at modern applications and services. It provides Single Sign-On (SSO), identity brokering, social login, user federation, and a comprehensive administration console. It supports OpenID Connect, OAuth 2.0, and SAML 2.0 protocols—everything you need to secure applications without building authentication from scratch.

My Opinion

Keycloak is the identity management solution that doesn’t lock you in. Auth0 charges you per user and limits your features. Okta requires you to sell your soul to enterprise sales. Keycloak gives you everything for free, and you own the infrastructure. For anyone building multiple applications under a single domain, it’s the obvious choice.

The Protocol Chameleon

Keycloak is a protocol chameleon. Need OAuth 2.0 for your SPA? Done. OpenID Connect for your mobile app? Easy. SAML for that legacy Java monolith you’re forced to maintain? Covered. The fact that it handles all of this from a single administration console means you don’t need to juggle multiple identity providers.

I use it to secure everything under dsalathe.dev—the blog, the games, the tools. One login, access everywhere.

The Administration Experience

This is where Keycloak shines. The admin console is comprehensive and intuitive. You can configure realms, clients, users, roles, and permissions through a web UI that actually makes sense. The user federation features are particularly powerful—you can pull users from LDAP, Active Directory, or social providers and manage them all centrally.

The Maintenance Tax

The downside is that you’re now running your own identity infrastructure. This means:

• Security patches are your responsibility
• High availability is your problem
• Database migrations require attention
• When something breaks, you’re on the hook

For organizations with DevOps teams, this is manageable. For small startups, the operational burden might outweigh the cost savings. But running Keycloak in Docker Compose for development is trivial, and production deployments behind Cloudflare tunnels are surprisingly straightforward.

The “Open Source” Reality

Keycloak is open source, but it’s sponsored by Red Hat. This means it’s well-maintained, but the documentation can be enterprise-speak heavy. The community is active, but finding answers for edge cases often involves digging through JIRA tickets and GitHub issues.

The good news: Red Hat’s backing means Keycloak isn’t going anywhere. The bad news: some features feel like they were designed for “enterprise requirements” rather than developer experience.

The Spring Integration

For Java developers using Spring, Keycloak integration is first-class. Spring Security’s OAuth2 support works seamlessly with Keycloak as the authorization server. The configuration is minimal, and you get production-ready authentication in hours, not weeks.

Conclusion

Keycloak is the best open-source identity management solution available. If you have the capacity to run and maintain your own identity infrastructure, it’s the clear winner over SaaS alternatives. If you don’t have that capacity, pay Auth0 for the peace of mind. See my detailed post on building SSO with Keycloak for implementation details and lessons learned.