Zitadel

Keycloak

keycloak/keycloak

Popular

CNCF open-source identity and access management server with SSO, OIDC, SAML and user federation.

Auth0

auth0.com

Popular

Okta-owned hosted identity platform with SDKs for every stack; a common enterprise default.

Okta

okta.com

Popular

Enterprise workforce identity and SSO platform; the standard for employee access to SaaS apps.

Microsoft Entra ID

microsoft.com

Popular

Microsoft's cloud identity service (formerly Azure AD) for Microsoft 365, Azure and enterprise SSO.

Clerk

clerk.com

Hosted auth and user management with drop-in UI components, popular in the Next.js ecosystem.

WorkOS

workos.com

Rising

APIs that add enterprise SSO, SCIM directory sync, audit logs and AuthKit to B2B SaaS apps.

Amazon Cognito

aws.amazon.com

AWS-managed user pools and identity federation for app sign-up, sign-in and access control.

authentik

goauthentik/authentik

Trending

Self-hosted identity provider with flows, SSO (OIDC/SAML/LDAP) and an app proxy; homelab and enterprise favorite.

Ory Kratos

ory/kratos

Headless, API-first identity and user management server (login, MFA, recovery) from Ory.