Top 5 authentication solutions for secure .NET apps in 2026

Authentication is a pivotal aspect of .NET applications, offering both robust built-in features and a variety of third-party solutions to enhance security and user management. Developers working on diverse projects, from B2B SaaS platforms to ASP.NET Core APIs, must choose the right authentication strategy to optimize development speed and feature capabilities. While ASP.NET Core Identity provides fundamental user management tools, it may not suffice for enterprise-level requirements such as SAML SSO and SCIM provisioning, which often necessitate specialized solutions. Several top authentication solutions for .NET are recommended, including WorkOS for its enterprise-specific features, ASP.NET Core Identity for its seamless integration within Microsoft's ecosystem, and IdentityServer for building custom OAuth2/OIDC servers. Azure AD B2C offers a consumer-focused approach with social authentication, and OpenIddict presents an open-source alternative for budget-conscious projects. The choice of an authentication provider significantly influences an application's scalability, security, and enterprise-readiness, and selecting a solution aligned with future needs can save substantial development time and effort.