Open Source Identity and Access Management for modern Applications and Services.




FusionAuth is described as 'Auth for any app. Get everything you need for secure registration and user management in minutes. Single-tenant, on-prem or private cloud, custom emails with localization, social login, and more' and is a identity management tool in the security & privacy category. There are more than 50 alternatives to FusionAuth for a variety of platforms, including Web-based, SaaS, Self-Hosted, Linux and Mac apps. The best FusionAuth alternative is Keycloak, which is both free and Open Source. Other great apps like FusionAuth are Authelia, authentik, AuthKit and Hanko.
Open Source Identity and Access Management for modern Applications and Services.




Protect your applications with Single Sign-On and 2 Factor. Authelia is an open-source full-featured authentication server available on Github.



authentik is an open-source identity provider focused on flexibility and versatility.




AuthKit is a Radix-powered open source authentication UI built for effortless customizations. User Management is the backend platform handling email verification, account linking, bot blocking, organization modeling, and more.




Hanko is a modern open source Authentication & User Management system – built and hosted in the EU. Alternative to Clerk, Auth0, Stytch, Descope.

Stack is an open-source, self-hostable, and highly customizable authentication and user management system.


Kanidm is an identity management server, acting as an authority on account information, authentication and authorisation within a technical environment.


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:



Phase Two builds on top of Keycloak, one of the most widely used open source identity and access management systems in the world. Our extensions bring multi-tenancy, audit logging, a self-service admin portal, and more to enhance Keycloak for SaaS and on-premise use cases.


Clerk is more than a "sign-in box." Integrate complete user management UIs and APIs, purpose-built for React, Next.js, and the Modern Web.

Amazon Cognito lets you add user sign-up/sign-in and access control to your web and mobile apps quickly and easily. Cognito scales to millions of users, and supports sign-in with social identity providers such as FB, Google, and Amazon, and SAML 2.0.

Okta's Workforce and Customer Identity Clouds enable secure access, authentication, and automation—putting identity at the heart of business security and growth.


