Keycloak vs ZITADEL
Both are alternatives to Auth0. Here's how they stack up — verified facts, no spin.
Keycloak
TOP PICKThe mature, CNCF-backed open-source identity and access management server.
Keycloak is a full-featured IAM server originally built by Red Bull's security team and now a CNCF Incubating project. It supports OIDC, OAuth2, and SAML, social and enterprise identity brokering, fine-grained authorization, and a built-in admin console, and it's the most widely deployed self-hosted alternative to Auth0/Okta in production today.
ZITADEL
A cloud-native, API-first identity platform with a generous self-hosted core.
ZITADEL is a modern identity and access management platform built API-first for cloud-native and multi-tenant SaaS use cases. It supports OIDC, SAML, passkeys/WebAuthn, and fine-grained actions/hooks for customizing the auth flow in code, and offers both a managed cloud and a self-hostable core.
Side by side
| Keycloak | ZITADEL | |
|---|---|---|
| Sovereignty Score | 90 | 82 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first | Yes | Yes |
| License | Apache-2.0 | AGPL-3.0 |
| Pricing | Free / self-host (Docker image or standalone distribution); commercial support available via Red Hat build of Keycloak (RHBK) for enterprises that want a support contract. | Free / self-host under AGPL-3.0; ZITADEL Cloud offers a managed free tier plus paid usage-based plans for teams that don't want to run the server themselves. |
Keycloak is Macrostack's recommended Auth0 alternative, so it's our pick here.
Keycloak
Strengths
- +Apache-2.0, fully open-source, no feature gating between a 'community' and 'enterprise' edition
- +Extremely mature — 10+ years in production at large scale, CNCF Incubating project with active governance
- +Broad protocol support (OIDC, SAML, OAuth2) and identity brokering to external IdPs out of the box
- +Large ecosystem of themes, extensions, and Kubernetes operators for production deployment
Trade-offs
- −Runs on the JVM — heavier resource footprint than lightweight Go-based alternatives, and the admin console/config model has a real learning curve
- −You own uptime, patching, and database backups for something security-critical — a genuine operational responsibility Auth0 absorbs for you
- −Theming the login UI to match a product's brand takes more custom work than Auth0's Universal Login customization
ZITADEL
Strengths
- +Strong native support for passkeys/WebAuthn and modern passwordless flows out of the box
- +API-first design and 'Actions' hooks make custom auth logic (e.g. custom claims, external calls during login) straightforward without forking the codebase
- +Built for multi-tenancy (organizations/projects) from the ground up, closer to Auth0's B2B model than most self-hosted options
- +Active development with frequent releases and a responsive open-source community
Trade-offs
- −AGPL-3.0 requires that any modified version offered as a network service also be released under AGPL — a real legal consideration for SaaS companies embedding it
- −Younger project than Keycloak with a smaller track record at very large scale
- −Some advanced features are positioned toward the paid ZITADEL Cloud tier rather than the self-hosted core
Facts verified 2026-07-14. Licenses and pricing change — spotted something out of date? That's a correction we want.