Fiddler 是一款免费的记录HTTP（S）通信的代理，支持监察请求和响应、设置断点，以及修改输入输出数据。
Fiddler is a Web Debugging Proxy which logs all HTTP(S) traffic between your computer and the Internet. Fiddler allows you to inspect all HTTP(S) 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.
官方网站：www.fiddlertool.com
系统支持：Windows 2000 / XP / 2003 / Vista with Microsoft .NET Framework v2.0 or later
Download：点击下载（Fiddler2Setup.exe，505.55KB）