IAM Comparison

Keycloak and Ory represent two fundamentally different philosophies in open-source identity. Keycloak is a batteries-included monolith — deploy one service, get everything. Ory is a modular microservices ecosystem — deploy only what you need, build your own UI. This comparison covers architecture, features, authorization, deployment, and when each approach wins. At a Glance Keycloak Ory Architecture Monolith (Java/Quarkus) Microservices (Go) License Apache 2.0 Apache 2.0 GitHub Stars ~25,000 (1 repo) ~39,000 (4 repos combined) Built-in UI Yes (admin + login pages) No (headless, API-first) SAML Support Yes (native) Enterprise only (Ory Polis) LDAP Federation Yes No Authorization UMA 2.0 + policies Zanzibar ReBAC (Keto) Multi-tenancy Realms (production-ready) Enterprise/Ory Network only Managed SaaS No official offering Yes (Ory Network) Min Resources ~512 MB RAM (JVM) ~128 MB RAM per service Architecture Keycloak: The Monolith Keycloak is a single Java application that handles everything: OIDC, SAML, user management, admin console, themes, session management, and authorization services. One deployment, one process, one configuration. ...

Keycloak and Authentik are the two most popular open-source identity platforms for self-hosted deployments. Keycloak brings enterprise maturity with 25,000+ GitHub stars and CNCF backing. Authentik brings modern developer experience with 20,000+ stars and rapid community growth. This comparison covers architecture, features, deployment, and when each is the right choice. At a Glance Keycloak Authentik Language Java (Quarkus) Python (Django) + Go outposts License Apache 2.0 MIT (core) + Enterprise License Database PostgreSQL, MySQL, Oracle, MSSQL PostgreSQL only GitHub Stars ~25,000 ~20,200 First Release 2014 2020 (originally “Supervisr”, 2018) Backing Red Hat / IBM, CNCF Incubating Authentik Security (Open Core Ventures) Multi-tenancy Realms (production-ready) Brands (cosmetic) + Tenants (alpha) FAPI Certified Yes (1.0 Advanced, all 8 profiles) No Min Resources 2 CPU / 2 GB RAM 2 CPU / 2 GB RAM Latest Version 26.x 2025.12.4 Architecture Keycloak Keycloak runs on the Quarkus framework (Java). A single binary handles all protocol endpoints (OIDC, SAML, LDAP), admin console, and account console. It stores sessions and configuration in an embedded Infinispan cache with database persistence. ...

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. ...

Choosing an Identity and Access Management (IAM) platform is one of the most consequential infrastructure decisions you will make. The platform you pick will touch every application, every user login, every API call, and every compliance audit for years to come. In 2026, three platforms dominate the conversation: Keycloak, Auth0, and Okta. I have deployed and managed all three in production environments ranging from startup MVPs to enterprise systems handling millions of authentications per day. This guide is the comparison I wish I had when I started evaluating these platforms. ...