Zitadel

Keycloak is the established open-source IAM platform with 41,000+ GitHub stars and CNCF backing. Zitadel is the challenger — a Go-based, event-sourced platform growing rapidly at 13,000+ stars. This comparison covers architecture, features, operations, and when each is the better choice. At a Glance Keycloak Zitadel Language Java (Quarkus) Go License Apache 2.0 AGPL-3.0 (v3+) GitHub Stars 41,000+ 13,000+ CNCF Status Incubating Not a CNCF project First Release 2014 2019 Maintainer Red Hat CAOS AG (Switzerland) Architecture Stateful (Infinispan cache) Stateless (event-sourced) Database PostgreSQL, MySQL, MariaDB, Oracle, MSSQL PostgreSQL only Cloud Offering Red Hat Build of Keycloak (subscription) Zitadel Cloud (free tier: 100 DAU) Architecture Keycloak Keycloak runs on Java/Quarkus with Infinispan for distributed session caching. A production deployment requires Keycloak nodes + an external database + Infinispan cluster configuration. Nodes are stateful — they hold session data in memory, requiring sticky sessions for optimal performance. ...