FusionAuth

FusionAuth is a complete identity and access management platform available as both a self-hosted solution and a managed cloud service. The platform provides authentication (email/password, social logins, passwordless, MFA), authorization (roles, groups, permissions), single sign-on across applications, user management, and multi-tenancy. FusionAuth supports all standard protocols including OAuth 2.0, OpenID Connect, SAML v2, and SCIM. The self-hosted Community edition is free with all core features, making it one of the most cost-effective auth solutions for teams that can manage their own infrastructure. Advanced features include lambda functions for customizing tokens and workflows, entity management for machine-to-machine auth, consent management for GDPR compliance, threat detection with rate limiting and CAPTCHA, custom registration forms, email templates, and webhook events. The admin UI provides comprehensive user management, application configuration, and tenant management. FusionAuth also offers family and parental controls for COPPA compliance, breach detection, and advanced threat intelligence. The platform can handle millions of users and supports horizontal scaling.