What should you compare in open-source authentication?

Protocols you need. User migration. Who operates the identity server

Does a sponsor change the order of this category?

No. Sponsor slots are labelled and sit outside the organic list.

Identity, login, and access control. Separate a login box for one app from single sign-on for many apps.

What to compare

Single sign-on and user federation for applications.

Often instead of Auth0

Authelia adds single sign-on and multifactor authentication to self-hosted apps.

An identity provider with flows you can edit.

Often instead of Auth0

ZITADEL provides identity management, SSO, passkeys, and multitenant login.

Often instead of Auth0

Ory Kratos provides login, registration, recovery, and identity management APIs.

An identity management server with user accounts, groups, and authentication policies.

Goiabada is an OAuth2 / OpenID Connect server written in Go.

What should you compare?: Protocols you need. User migration. Who operates the identity server.
Does a sponsor change the order?: No. Sponsor slots are labelled and sit outside the organic list.

Repository activity is a signal, not a security or quality guarantee. Snapshot: October 1, 2026.