Keycloak

Open-source · self-hostable · replaces 1 SaaS tool on os-alt

keycloak/keycloak · alive · ★ 34.4k · last commit today · 2804 open issues

License: Apache-2.0

Good fit for B2B apps that want SAML + OIDC + LDAP federation in one server, and don't mind Java footprint.

Weak at Java-heavy; theming and UX out of the box are dated vs Auth0.

In a terminal? npx -y github:SolvoHQ/os-alt-cli auth0 prints the Auth0 comparison table including Keycloak. how the CLI works →

Replaces these SaaS

Auth0 · Identity / SSO / authentication-as-a-service
Auth0 → Tenant → Export users (JSON, including hashed passwords if on bcrypt). Keycloak → Admin Console → realm-import via JSON or the Keycloak `kcadm.sh` CLI. Bcrypt hashes import directly — users keep their passwords. Map Auth0 Rules / Actions to Keycloak event listeners or authentication-flow scripts.

Maintainers and forks: drop a badge in your README to link readers from the SaaS-comparison page back to your repo.

Is Keycloak actively maintained?

Yes — last commit today. The repository is alive (commit activity within the past 90 days).

What does Keycloak cost to self-host?

Keycloak is free and open source under Apache-2.0. Typical self-host VPS cost: $10 VPS for a small team; $20+ for production with HA Postgres.

Which SaaS does Keycloak replace?

Keycloak is listed as an open-source self-host alternative to: Auth0.