Keycloak vs WSO2 Identity Server
A side-by-side comparison of two self-hosted identity & sso options — licensing, setup difficulty, resource needs, and what each one replaces.
Keycloak
Open-source identity and access management for modern apps
VS
WSO2 Identity Server
Open-source identity and access management server
| Feature | Keycloak | WSO2 Identity Server |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 99 · Excellent | 80 · Excellent |
| Category | Identity & SSO | Identity & SSO |
| License | Apache-2.0 | Apache-2.0 |
| Language | Java | Java |
| Setup difficulty | Hard | Hard |
| Min. RAM | 1,024 MB | 4,096 MB |
| Deployment | docker, kubernetes, bare-metal | docker, kubernetes, bare-metal |
| GitHub stars | ★ 36,967 | ★ 880 |
| First released | 2014 | 2007 |
| Replaces | Okta, Auth0, Microsoft Entra ID | Okta, ForgeRock |
What are Keycloak and WSO2 Identity Server?
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
WSO2 Identity Server
WSO2 Identity Server is an open-source IAM product that provides single sign-on, identity federation, and strong authentication. It supports SAML, OpenID Connect, and adaptive authentication policies.
- Single sign-on
- Identity federation
- Adaptive authentication
- Standards support
Keycloak vs WSO2 Identity Server: key differences
Both projects are written in Java. Keycloak is the lighter option, starting around 1,024 MB of RAM against 4,096 MB for WSO2 Identity Server. WSO2 Identity Server is the more established project (first released 2007), while Keycloak arrived in 2014. Keycloak has the considerably larger community, at 36,967 GitHub stars versus 880.
Why pick each one
Choose Keycloak if…
- Mature and battle-tested
- Strong enterprise feature set
Watch out for
- Steep learning curve
- Resource intensive
Choose WSO2 Identity Server if…
- Enterprise feature set
- Strong standards coverage
Watch out for
- Resource heavy
- Complex tuning
Frequently asked questions
Is Keycloak or WSO2 Identity Server 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 Keycloak and WSO2 Identity Server free and open-source?
Yes. Keycloak is licensed under Apache-2.0 and WSO2 Identity Server under Apache-2.0. Both can be self-hosted at no software cost.
Can I run Keycloak and WSO2 Identity Server with Docker?
Keycloak: yes. WSO2 Identity Server: yes.
Which is lighter on resources, Keycloak or WSO2 Identity Server?
Keycloak has the smaller minimum footprint at 1,024 MB of RAM, compared to about 4,096 MB for WSO2 Identity Server. Real-world usage depends on library size, user count, and enabled features.