Charles is a web proxy (HTTP Proxy / HTTP Monitor) that runs on your own computer. Your web browser (or any other Internet application) is then configured to access the Internet through Charles, and Charles is then able to record and display for you all of the data that is sent and received.
In Web and Internet development you are unable to see what is being sent and received between your web browser / client and the server. Without this visibility it is difficult and time-consuming to determine exactly where the fault is. Charles makes it easy to see what is happening, so you can quickly diagnose and fix problems.
Charles makes debugging quick, reliable and advanced; saving you time and frustration!
• SSL Proxying – view SSL requests and responses in plain text
• Bandwidth Throttling to simulate slower Internet connections including latency
• AJAX debugging – view XML and JSON requests and responses as a tree or as text
• AMF – view the contents of Flash Remoting / Flex Remoting messages as a tree
• Repeat requests to test back-end changes
• Edit requests to test different inputs
• Breakpoints to intercept and edit requests or responses
• Validate recorded HTML, CSS and RSS/atom responses using the W3C validator
What's New in Charles 3.6.5
Major bug fixes:
Java 1.7 now supported. Corrects slow startup and hung responses bugs.
Java 1.7 bad certificate error workaround for sites that use now disabled algorithms (ie. MD2withRSA)
Windows: Fix launching Charles by opening a file
SSL empty requests regression from 3.6.4 fixed
...See Full Release Notes
Charles is a Java application, it requires version 1.4 or later of the JRE or JDK from Sun. You probably already have the JRE or JDK on your computer as it comes with many operating systems. When you try to run Charles it will notify you if you don't have the necessary software.