Apereo CAS vs Keycloak
A side-by-side comparison of two self-hosted identity & sso options — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
Apereo CAS
Enterprise single sign-on server for web applications
VS
Keycloak
Open-source identity and access management for modern apps
| Feature | Apereo CAS | Keycloak |
|---|---|---|
| Category | Identity & SSO | Identity & SSO |
| License | Apache-2.0 | Apache-2.0 |
| Language | Java | Java |
| Setup difficulty | Hard | Hard |
| Min. RAM | 1,024 MB | 1,024 MB |
| Deployment | docker, kubernetes, bare-metal | docker, kubernetes, bare-metal |
| GitHub stars | ★ 11,354 | ★ 36,058 |
| First released | 2004 | 2014 |
| Replaces | Okta, Ping Identity | Okta, Auth0, Microsoft Entra ID |
Why pick each one
Choose Apereo CAS if…
- Mature SSO with broad protocol support
- Widely adopted in academia
Frequently asked questions
Is Apereo CAS or Keycloak better?
Neither is universally better. Keycloak has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Apereo CAS and Keycloak free and open-source?
Yes. Apereo CAS is licensed under Apache-2.0 and Keycloak under Apache-2.0. Both can be self-hosted at no software cost.
Can I run Apereo CAS and Keycloak with Docker?
Apereo CAS: yes. Keycloak: yes.