Charles

Charles is an app that allows you to analyze, monitor and debug HTTP and HTTPS web traffic. Charles functions as an HTTP/HTTPS proxy that captures and intercepts all network traffic in real time, allowing you to examine HTTP requests, responses and headers in the greatest possible level of detail. The app natively supports WebSockets and allows both encrypted and unencrypted content to be inspected, thanks to its SSL certificate system that acts as a trusted certificate authority to securely decrypt HTTPS traffic.

Automatic configuration

Charles allows you to automatically configure proxy settings in Windows, macOS and browsers like Firefox. On Windows, the app configures the operating system settings so the web browser and other apps use Charles automatically.

Advanced analysis

Charles also gives you the chance to pause requests and responses to modify them before they reach the server or client. The bandwidth throttling function simulates slow network conditions, which is ideal for testing how apps perform at different connection speeds. What's more, you also have automatic request rewriting capabilities that facilitate the modification of headers, HTTP methods or URLs for specific tests and advanced debugging.

Special functions for mobile development

The app supports iOS and Android handsets, allowing you to capture and analyze mobile app traffic when the devices are connected to the same WiFi network. For mobile devices, Charles presents simplified SSL certificate installation via the URL chls.pro/ssl, so inspecting HTTPS traffic on smartphones and tablets is a breeze. This is especially handy if you are a mobile app developer and need to debug communications and analyze an app's network behavior.

Session export and collaboration

Charles allows you to save and export complete sessions of captured traffic, making for easier offline analysis and collaboration between development teams. Data can be exported in various formats, including HAR and SAZ, which are compatible with other web analysis tools. The app also supports session imports, allowing you to review traffic captures made or shared by other developers in the team at an earlier time.

Reverse proxy and forwarding capabilities

Charles's reverse proxy functionality allows you to redirect traffic to specific servers, a feature that is especially useful when testing APIs in staging and local development environments. The port forwarding system includes support for port ranges and UDP forwarding, expanding the configuration possibilities for complex network settings. These capabilities make the app ideal for both frontend and backend development, offering great flexibility for different app architectures.

Download Charles for advanced web traffic analysis and debugging.