Fiddler

Fiddler is a family of web debugging proxies published by Progress (Telerik). They capture, inspect and modify HTTP and HTTPS traffic between applications and servers, compose and replay requests, and help debug web, mobile and API traffic.

Fiddler Everywhere runs on Windows, macOS and Linux and is licensed for professional use; Fiddler Classic is available for eligible non-commercial use; Fiddler Everywhere Reporter is a free capture tool; FiddlerCore is a .NET library for embedding traffic capture in applications. Free trials are available.