Authelia is described as 'Protect your applications with Single Sign-On and 2 Factor.
Authelia is an open-source full-featured authentication server available on Github' and is a identity management tool in the security & privacy category. There are more than 10 alternatives to Authelia for a variety of platforms, including Self-Hosted, SaaS, Web-based, Docker and Linux apps. The best Authelia alternative is Keycloak, which is both free and Open Source. Other great apps like Authelia are VoidAuth, authentik, ZITADEL and Auth0.