Microsoft Entra ID

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.

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.

Zitadel

zitadel/zitadel

Rising

Cloud-native, multi-tenant identity platform with OIDC, SAML, passkeys and an event-sourced core.

Ory Kratos

ory/kratos

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