HTTP Debugging Proxy,logs all HTTP traffic between computer and the Internet. Fiddler is a HTTP Debugging Proxy which logs all HTTP traffic Between your computer and the Internet. Fiddler allows you to inspect all HTTP Traffic, set breakpoints, and 'fiddle' with incoming or outgoing data. Fiddler includes a powerful event-based scripting subsystem, and can be extended using any .NET language.
Fiddler is freeware and can debug traffic from virtually any application, including Internet Explorer, Mozilla Firefox, Opera, and thousands more.
Version 2.3.2.3- Improved Performance
- Improved Autoresponder
- Improved support for Windows Phone emulator
- Edit preferences with about:config
- Various small improvements
Lots of bugfixes you can free
download Fiddler 2.3.4.2 now.