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Ory Hydra vs Ory Kratos

A side-by-side comparison of two self-hosted identity & sso options — licensing, setup difficulty, resource needs, and what each one replaces.

Not the right match-up?
OR Ory Hydra Certified OAuth 2.0 and OpenID Connect server VS OR Ory Kratos Headless identity and user management API server
FeatureOry HydraOry Kratos
Deploy effortUnder-an-hour setupUnder-an-hour setup
Health score90 · Excellent89 · Excellent
CategoryIdentity & SSOIdentity & SSO
LicenseApache-2.0Apache-2.0
LanguageGoGo
Setup difficultyHardHard
Min. RAM256 MB256 MB
Deploymentdocker, kubernetes, binarydocker, kubernetes, binary
GitHub stars★ 17,563★ 13,888
First released20152020
ReplacesOkta, Auth0Auth0, Firebase Auth

What are Ory Hydra and Ory Kratos?

Ory Hydra

Ory Hydra is an OpenID Certified OAuth 2.0 and OpenID Connect provider. It is built to integrate with any existing identity system and issues tokens without managing user accounts itself.

  • OpenID Certified implementation
  • Low memory footprint
  • Bring your own login and consent UI
  • Scales horizontally

Read the full Ory Hydra guide →

Ory Kratos

Ory Kratos is an API-first identity and user management system. It handles login, registration, profile management, account recovery and multi-factor authentication without prescribing a user interface.

  • Headless API for full UI control
  • Self-service flows for login and recovery
  • Pluggable MFA including TOTP and WebAuthn
  • Cloud-native and stateless design

Read the full Ory Kratos guide →

Ory Hydra vs Ory Kratos: key differences

Both projects are written in Go. Ory Hydra is the more established project (first released 2015), while Ory Kratos arrived in 2020.

Why pick each one

Choose Ory Hydra if…

  • Security focused and certified
  • Integrates with any user store

Watch out for

  • Only handles OAuth, not user management
Ory Hydra details

Choose Ory Kratos if…

  • Extremely flexible architecture
  • Excellent for custom frontends

Watch out for

  • Requires building your own UI
  • Complex initial setup
Ory Kratos details

Frequently asked questions

Is Ory Hydra or Ory Kratos better?

Neither is universally better. Ory Hydra has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.

Are Ory Hydra and Ory Kratos free and open-source?

Yes. Ory Hydra is licensed under Apache-2.0 and Ory Kratos under Apache-2.0. Both can be self-hosted at no software cost.

Can I run Ory Hydra and Ory Kratos with Docker?

Ory Hydra: yes. Ory Kratos: yes.

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