When developing Flash application that make use of the network capabilities of Flash it is difficult to debug as you cannot see the requests and responses. Charles negates this difficulty by making every HTTP request and response easily visible.

Whereas other Flash debuggers only work inside the Flash development environment, Charles sits between your web browser and the Internet - so you can test your movies in Internet Explorer or Netscape. However Charles will work on Flash movies run inside Flash as well.

The bandwidth profiler inside the Flash development environment is useful when testing movies, however it cannot give an accurate picture of an entire website. Charles can throttle your Internet connection itself so that you can browse your Flash website as a modem user might see it.

Charles now has port forwarding support which enables you to debug your XMLSocket connections as well.