What is Ory Kratos used for?

Ory Kratos is an API-first identity and user management system written in Go, covering login, registration, recovery and MFA, as an alternative to Auth0 and Firebase. It is a good fit for replacing Auth0 or Firebase Authentication, adding login flows to Kubernetes-based services and centralizing user management across applications.

Is Ory Kratos open source?

Yes. Ory Kratos is open source under the Apache-2.0 licence. Its source code is on GitHub at ory/kratos and is written mainly in Go.

Yes. Ory Kratos is open source, so the software itself is free to use. A managed cloud version is also available, with paid plans from $770 per year.

Can I self-host Ory Kratos?

Yes. Ory Kratos can be self-hosted on your own server or infrastructure.

What is Ory Kratos an alternative to?

Ory Kratos is an open-source alternative to Auth0, Firebase, Clerk and FusionAuth. Other open-source alternatives to Auth0 include SuperTokens, ZITADEL and Authgear.

Is Ory Kratos actively maintained?

Yes. The most recent commit to Ory Kratos was on 29 July 2026, and the latest release is v26.2.0, published on 20 March 2026. The project has 14k stars on GitHub.

Ory Kratos: open-source alternative to Auth0, Firebase

About Ory Kratos

Ory Kratos is a headless identity and user management system for cloud-native applications. It centralizes login, registration, account recovery, verification and profile management so that services call it over HTTP APIs instead of reimplementing those flows, and it works with any UI framework through browser and native app flows.

Supported capabilities include self-service login and registration, multi-factor authentication, social sign-in, OIDC, passkeys, magic links, SMS and TOTP, along with configurable identity schemas and traits and admin APIs for managing the identity lifecycle. It integrates with the wider Ory stack for OAuth2, OpenID Connect and access control.

Kratos is an open-source alternative to hosted identity providers such as Auth0 and Firebase, and the README suggests pairing it with Ory Hydra when migrating from Auth0 or Okta using OAuth2 or OpenID Connect. It is licensed under Apache-2.0 and written in Go, and it can be self-hosted or used through the managed Ory Network.

Key features

Self-service login and registration flows
Account verification and recovery
Multi-factor authentication and passkeys
Social sign-in and OIDC
Identity schemas with custom traits
Admin APIs for identity lifecycle
Headless design that works with any UI

Good fit for

→Replacing Auth0 or Firebase Authentication
→Adding login flows to Kubernetes-based services
→Centralizing user management across applications

Built with: Go
Tags: authentication; identity; iam; user-management; passkeys; oidc; go; mfa; self-hosted

Ory Kratos: questions and answers

What is Ory Kratos used for?: Ory Kratos is an API-first identity and user management system written in Go, covering login, registration, recovery and MFA, as an alternative to Auth0 and Firebase. It is a good fit for replacing Auth0 or Firebase Authentication, adding login flows to Kubernetes-based services and centralizing user management across applications.
Is Ory Kratos open source?: Yes. Ory Kratos is open source under the Apache-2.0 licence. Its source code is on GitHub at ory/kratos and is written mainly in Go.
Is Ory Kratos free?: Yes. Ory Kratos is open source, so the software itself is free to use. A managed cloud version is also available, with paid plans from $770 per year.
Can I self-host Ory Kratos?: Yes. Ory Kratos can be self-hosted on your own server or infrastructure.
What is Ory Kratos an alternative to?: Ory Kratos is an open-source alternative to Auth0, Firebase, Clerk and FusionAuth. Other open-source alternatives to Auth0 include SuperTokens, ZITADEL and Authgear.
Is Ory Kratos actively maintained?: Yes. The most recent commit to Ory Kratos was on 29 July 2026, and the latest release is v26.2.0, published on 20 March 2026. The project has 14k stars on GitHub.