Keycloak vs Ory Kratos
Both are alternatives to Auth0. Here's how they stack up — verified facts, no spin.
Also searched as Ory Kratos vs Keycloak — same comparison, one verdict.
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.
Ory Kratos
A headless, API-only identity server for teams that want to build their own login UI.
Ory Kratos is a headless identity and user-management server — it handles registration, login, MFA, account recovery, and profile management entirely through APIs, with no bundled UI. It's designed for teams who want full control over the login experience and are comfortable building their own frontend against a well-documented identity API.
Side by side
| Keycloak | Ory Kratos | |
|---|---|---|
| Sovereignty Score | 90 | 84 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first | Yes | Yes |
| License | Apache-2.0 | Apache-2.0 |
| 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 Apache-2.0; Ory Network offers a managed hosted version with a free tier and paid usage-based plans for teams that prefer not to operate it 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
Ory Kratos
Strengths
- +Clean Apache-2.0 license with no enterprise-only carve-out directory, unlike several peers
- +Headless-by-design means zero UI lock-in — build exactly the login experience your product needs
- +Pairs well with companion Ory projects (Hydra for OAuth2/OIDC server, Keto for permissions) for teams that need the full stack
- +Strong documentation and a security-first design philosophy from the Ory team
Trade-offs
- −Headless-only means you must build and maintain your own login/registration UI — meaningfully more upfront engineering work than Auth0's Universal Login or authentik's flow builder
- −Running the full picture (Kratos + Hydra + Keto) for OAuth2/OIDC server capability adds operational complexity beyond a single service
- −Smaller ecosystem of ready-made UI kits/themes compared to Keycloak or authentik
Related alternative guides
Facts verified 2026-07-14. Licenses and pricing change — spotted something out of date? That's a correction we want.