Download Charles – HTTP Proxy for Mac, Windows, Linux

Overview

Charles Web Debugging Tool is a Java‑based HTTP proxy and monitoring utility that gives developers full visibility into the traffic flowing between their computer and the Internet. Originally built for macOS, Charles now runs on Windows and Linux as well, making it a cross‑platform staple for anyone who needs to inspect, modify, or replay HTTP and HTTPS requests. By acting as a man‑in‑the‑middle proxy, Charles captures every request header, response body, cookie, and caching directive, allowing you to troubleshoot API calls, debug AJAX calls, and verify the content of secure HTTPS sessions without ever leaving your development environment.

One of the standout capabilities is bandwidth throttling – the tool can simulate dial‑up, 3G, or custom network conditions, which is especially valuable for Flash, mobile, and responsive‑design testing. Recent updates have added Java 1.7 compatibility, fixed slow‑startup bugs, and improved SSL error handling, ensuring that the application remains fast, stable, and secure on modern systems. Whether you’re building a single‑page application, integrating a third‑party API, or simply need to see what data your browser is sending, Charles offers an intuitive UI, powerful filters, and a rich set of features that turn opaque network traffic into an actionable debugging resource.

Key Features

• Full HTTP/HTTPS Inspection: Capture request and response headers, bodies, cookies, and authentication details for any protocol.
• SSL Proxying: Decrypt and view encrypted traffic with a one‑click trust‑store installation, making HTTPS debugging painless.
• Bandwidth Throttling: Simulate slow connections (dial‑up, 3G, custom) to test performance under realistic network conditions.
• Reverse Proxy Mode: Act as a server‑side proxy to test how your application behaves when placed behind a gateway.
• Request/Response Editing: Modify headers or bodies on the fly and resend requests to see how servers react.
• XML/AJAX Support: Dedicated view for XML, JSON, and AJAX calls, with pretty‑printing and syntax highlighting.
• Session Recording & Export: Save entire browsing sessions and export them in HAR, XML, or CSV for sharing with teammates.
• Cross‑Platform Java Engine: Runs on macOS, Windows, and Linux without needing separate binaries for each OS.
• Search & Filter: Powerful search bar and filter rules let you isolate traffic from specific domains, MIME types, or status codes.
• Automation Friendly: Command‑line options and scripting hooks enable integration with CI pipelines and automated tests.

Installation & Usage Instructions

Installing Charles is straightforward thanks to its Java foundation. Begin by ensuring that Java 1.7 or later is installed on your machine; you can download the latest JRE from Oracle’s website or adopt OpenJDK if you prefer an open‑source runtime. Once Java is in place, download the appropriate installer from the official Charles website. macOS users receive a .dmg file that can be dragged into the Applications folder, while Windows users get a standard .exe installer and Linux users a .tar.gz archive that can be extracted to any directory.

After installation, launch Charles and grant the necessary network permissions. On macOS, you’ll be prompted to allow the application to configure the system proxy; accept the dialog so that all traffic is automatically routed through Charles. Windows may require you to run the program as an administrator for the same reason. The first time you start Charles, the UI presents a three‑pane layout: a tree view of recorded sessions on the left, a detailed request/response view in the center, and a timeline/sequence view on the right. To begin capturing traffic, simply open your web browser or API client and browse as usual – Charles will populate the session list in real time.

To inspect HTTPS traffic, navigate to Proxy → SSL Proxying Settings, enable SSL proxying, and add the domains you wish to decrypt (or use “*” to capture all). Charles will then generate a root certificate that you must install into your system’s trusted store; detailed steps are provided within the app. Bandwidth throttling can be activated via Proxy → Throttle Settings**, where you choose a preset speed or define a custom latency and bandwidth limit. For developers working with APIs, the “Repeat” and “Rewrite” tools allow you to resend modified requests without leaving the interface, dramatically speeding up debugging cycles.