HTTP Toolkit is an elegant, cross-platform, open-source debugging proxy, analyser and HTTP(S) client, with built-in support for modern tools, from Docker to Android and GraphQL. It can be set up with a single click to start seeing exactly what is being sent. You can compare requests or responses and explore overall metrics to understand everything in depth. Traffic can be rewritten in real time, and errors or performance problems simulated, to test the system. You can also quickly prototype requests or responses, from real traffic or from scratch, and export them as shareable recordings or ready-to-use code.