Keycloak vs FusionAuth
The two names that come up when a team wants to run identity itself rather than rent it.
The one-line difference
Keycloak is the leading open-source IAM server, fully free and self-hosted, backed by Red Hat. FusionAuth is a single deployable application offered free or commercially, with licensing that does not scale per monthly active user and a polished admin experience.
Where Keycloak wins
- Fully open source with no licensing cost
- Standards-heavy: SAML, OIDC, and LDAP native
- Large community and complete control over the deployment
Where FusionAuth wins
- Easier to operate, with a cleaner admin UI and support options
- Predictable licensing not tied to per-MAU pricing
- Cloud, self-hosted, and hybrid deployment from one product
The honest call
If you have the DevOps capacity and want a free, fully open platform, Keycloak is the default. If you want self-hosting without the operational weight, plus paid support and a smoother admin path, FusionAuth earns its license. Both fit data-residency and on-prem requirements; weigh ops effort against support. See the pricing guide and the matcher.