Keycloak alternatives: 6 apps ranked by verified data

Facts checked Oct 25, 2026AppBreakup editorialHow we rank

Common reasons people leave Keycloak: you run, scale and upgrade it yourself, and admin concepts and theming have a steep learning curve. We ranked 6 alternatives by how directly each one replaces Keycloak, then by reviews, real visits and how recently each app's facts were checked against its own website. Zitadel currently ranks first.

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The best Keycloak alternative for…

The highest-ranked app in this list for each need.

Best Keycloak alternative for most people

Zitadel

Modern open-source alternative with a friendlier UI and a managed cloud if you want it.

Best Keycloak alternative for a free option

authentik

Easier to configure, with a built-in application proxy, LDAP and RADIUS.

Best Keycloak alternative for a free plan you can upgrade

FusionAuth

Self-hostable server with a cleaner API and optional paid support and hosting.

Best Keycloak alternative for open source

Ory

Headless, API-first components for teams that want to build their own login UI.

Best Keycloak alternative for self-hosting

Casdoor

Lightweight open-source IAM with a simple web UI and many identity providers.

Best Keycloak alternative for Mac

FusionAuth

Self-hostable server with a cleaner API and optional paid support and hosting.

Best Keycloak alternative for Windows

FusionAuth

Self-hostable server with a cleaner API and optional paid support and hosting.

Best Keycloak alternative for Linux

FusionAuth

Self-hostable server with a cleaner API and optional paid support and hosting.

Best Keycloak alternative for working in the browser

Auth0

Fully managed, so nobody on the team has to run identity servers.

Keycloak alternatives: common questions

What is the best alternative to Keycloak?

Zitadel ranks first right now. Modern open-source alternative with a friendlier UI and a managed cloud if you want it. authentik and FusionAuth follow it in our ranking.

Is there a free alternative to Keycloak?

Yes. Zitadel (open source), authentik (open source), FusionAuth (free plan + paid) and Ory (open source) have a free option. Check each app's verified facts for current plan limits.

Is there an open-source alternative to Keycloak?

Yes: Zitadel, authentik, Ory and Casdoor. Zitadel, authentik and Ory can also be self-hosted.

Which Keycloak alternatives work on Linux?

FusionAuth runs on Linux.

Why do people switch from Keycloak?

The complaints we hear most: you run, scale and upgrade it yourself; admin concepts and theming have a steep learning curve; login pages look dated without custom themes.

How is this list ranked?

Every app is scored with the same published formula: how directly it replaces Keycloak, reviews (weighted by verification), visits from AppBreakup, how recently its facts were checked against its own website, and reader votes.