Charles

Charles is an HTTP proxy, HTTP monitor and reverse proxy that lets developers view all HTTP and HTTPS traffic between their machine and the Internet, including requests, responses, cookies and headers. It can decrypt SSL/HTTPS traffic, simulate slower network connections, and provides download statistics. It is used to debug web and mobile applications.

Charles is developed by XK72 and runs on Windows, macOS and Linux. It is sold as a per-user licence after a 30-day free trial; version 5.1 was released in April 2026.