Ory Kratos vs ZITADEL
Both are alternatives to Auth0. Here's how they stack up — verified facts, no spin.
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.
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
| Ory Kratos | ZITADEL | |
|---|---|---|
| Sovereignty Score | 84 | 82 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first | Yes | Yes |
| License | Apache-2.0 | AGPL-3.0 |
| Pricing | 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. | 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. |
Ory Kratos edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
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
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.