Charles Proxy
Charles Proxy is a debugging proxy tool that lets testers intercept, inspect, and manipulate HTTP and HTTPS traffic between an application and the network — viewing raw requests and responses, simulating slow or unreliable connections, and mocking server responses without changing any code.
Positioned between a client and the internet, Charles captures every request and response passing through it, letting a tester inspect exact headers, payloads, and timing — invaluable for debugging why a mobile app or web page is behaving unexpectedly when the cause isn't obvious from the UI alone.
Its throttling and breakpoint features are particularly useful for testing edge cases that are otherwise hard to reproduce on demand — simulating a slow 3G connection, forcing a specific request to fail, or rewriting a response on the fly to test how the client handles an unexpected payload, all without touching the actual server.
