FusionAuth vs Keycloak
A side-by-side comparison of two self-hosted identity & sso options — licensing, setup difficulty, resource needs, and what each one replaces.
FusionAuth
Complete authentication and authorization platform
VS
Keycloak
Open-source identity and access management for modern apps
| Feature | FusionAuth | Keycloak |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 70 · Good | 99 · Excellent |
| Category | Identity & SSO | Identity & SSO |
| License | Apache-2.0 | Apache-2.0 |
| Language | Dockerfile | Java |
| Setup difficulty | Medium | Hard |
| Min. RAM | 1,024 MB | 1,024 MB |
| Deployment | docker, kubernetes, bare-metal | docker, kubernetes, bare-metal |
| GitHub stars | ★ 241 | ★ 36,967 |
| First released | 2018 | 2014 |
| Replaces | Auth0, Okta | Okta, Auth0, Microsoft Entra ID |
What are FusionAuth and Keycloak?
FusionAuth
FusionAuth is a self-hostable customer identity and access management platform supporting OAuth, OIDC, SAML, MFA, and user management. The community edition runs free on your own infrastructure.
- OAuth, OIDC and SAML support
- Multi-factor authentication
- User and tenant management
- Themable login pages
Keycloak
Keycloak is an enterprise-grade identity and access management solution backed by Red Hat. It provides single sign-on, identity brokering, social login and fine-grained authorization for applications and services.
- SSO with OpenID Connect and SAML 2.0
- Identity brokering and social login
- User federation with LDAP and Active Directory
- Fine-grained authorization services
FusionAuth vs Keycloak: key differences
FusionAuth is written in Dockerfile, while Keycloak is built with Java. Keycloak is the more established project (first released 2014), while FusionAuth arrived in 2018. Keycloak has the considerably larger community, at 36,967 GitHub stars versus 241.
Why pick each one
Choose FusionAuth if…
- Released under the Apache-2.0 license
- First-class Docker support for quick deployment
- Kubernetes-ready with Helm charts available
- Written in Dockerfile
Choose Keycloak if…
- Mature and battle-tested
- Strong enterprise feature set
Watch out for
- Steep learning curve
- Resource intensive
Frequently asked questions
Is FusionAuth or Keycloak better?
Neither is universally better. Keycloak has the larger community, while FusionAuth is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are FusionAuth and Keycloak free and open-source?
Yes. FusionAuth is licensed under Apache-2.0 and Keycloak under Apache-2.0. Both can be self-hosted at no software cost.
Can I run FusionAuth and Keycloak with Docker?
FusionAuth: yes. Keycloak: yes.