Audience
Developers, web owners and organizations seeking a cross-platform web server for ASP.NET Core
About Kestrel
Kestrel is a cross-platform web server for ASP.NET Core. Kestrel is the web server that's included and enabled by default in ASP.NET Core project templates. Kestrel supports HTTPS, HTTP/2 (except on macOS), Opaque upgrade used to enable WebSockets, Unix sockets for high performance behind Nginx. Kestrel is supported on all platforms and versions that .NET Core supports. Some browsers require granting explicit permission to trust the local development certificate. Project templates configure apps to run on HTTPS by default and include HTTPS redirection and HSTS support. The Kestrel web server has constraint configuration options that are especially useful in Internet-facing deployments. There's a separate limit for connections that have been upgraded from HTTP or HTTPS to another protocol (for example, on a WebSockets request). The default maximum request body size is 30,000,000 bytes, which is approximately 28.6 MB.