Debugging with Fiddler

1 minute read


Well, download Fiddler first by visiting


Use BeyondCompare to compare web sessions

Everyone loves BeyondCompare, isn't it?. At least, it's my favourite comparison tool. I know the tool and feels comfortable with it.

To set it on Fiddler, open QuickExce box by pressing alt + q. Then type the following commands there. The path to BC can be different depending on your installation. (from fiddler's CompareTool help)

[sourcecode language="bash"]<br>about:config<br>PREFS SET fiddler.config.path.differ "C:\Program Files (x86)\Beyond Compare 3\"<br>PREFS SET fiddler.differ.Params "/diff \"{0}\" \"{1}\""<br>[/sourcecode]

Now, when you select two web sessions and press ctrl + w, you can compare those sessions against each other on beyond

Script editor

It's a text editor that helps you edit script rules and offers syntax highlighting and a class explorer (really useful) to help you author scripts. Get the installer with screenshot from FiddlerScript page.

Before you start installation, you need close your Fiddler.

With script editor, you can add a custom column.

Keyboard shortcuts

I love keyboard shortcuts.

  • ctrl + c: copy, ctrl + a: select all
  • ctrl + g: go to a specific line number
  • ctrl + alt + f: activate the Fiddler window
  • ctrl + m: minimise Fiddler
  • alt + q: set focus to the QuckExec box
  • ctrl + t: activate inspector
  • ctrl + w: compare sessions
  • ctrl + shft + del: Clear the WinINET cache