[voidmain (accepted answer)] First of, FusionAuth is free. Developers can use it for any application and even deploy to production with any number of users. All of the features of FusionAuth are available for free as well. FusionAuth provides all of the core features that an identity provider must provide. These include registration, login, SSO, MFA, password hashing, password constraints, password reset, email templates, OAuth, OpenID Connect and others. In addition to the core features, FusionAuth also provides localization features, reporting, analytics, user segmentation, user search and a user management UI. FusionAuth is single-tenant and downloadable. You can download it to your dev box, deploy it on a bare-metal server, run it in any cloud or deploy it to Docker. This provides a lot flexibility and FusionAuth (the company) can host it for you in an AWS private cloud if you need. Finally, FusionAuth is built to scale.

Context: Stack Overflow #52670804 (accepted answer, 15 votes, 2 answers): We're checking out Auth Providers and was wondering how FusionAuth compares to the others?