Authelia is described as 'uthelia is an open-source authentication and authorization server providing two-factor authentication and single sign-on (SSO) for your applications via a web portal'. There are five alternatives to Authelia for a variety of platforms, including Self-Hosted solutions, Linux, Online / Web-based, Zen Cart and X-Cart Store Manager. The best alternative is Keycloak, which is both free and Open Source. Other great apps like Authelia are Auth0 (Freemium), LoginRadius (Paid), Pomerium (Free Personal, Open Source) and authentik (Free, Open Source).
You can connect any application (written in any language or on any stack) to Auth0 and define its Connection, the method used to authenticate the users of that application: • Custom credentials: username + passwords • Social network logins: Google, Facebook, Twitter...
Pomerium is an identity-aware proxy that enables secure access to internal applications. Pomerium provides a standardized interface to add access control to applications regardless of whether the application itself has authorization or authentication baked-in.
authentik is an open-source identity provider focused on flexibility and versatility. - Easy to Use: Identity made easy. authentik makes single-sign on (SSO), user enrollment, and access control simple.