• .NET

    Help! Running Fiddler Fixes My App???

    Over the years, the most interesting class of support requests for Fiddler are of the form: “My application or website is failing, but when I try to capture a repro with Fiddler, the problem goes away completely! How is Fiddler fixing it?”
    February 28, 2013
  • .NET

    Testing HTML5 AppCache with Fiddler

    A few weeks back, Jonathan Sampson noted that testing the HTML5 AppCache feature is a bit of a pain. One reason is that, in IE10, putting the browser into Work Offline mode is ineffective—the browser will detect that a network connection is available and exit the Work Offline mode automatically.
    February 15, 2013
  • .NET

    Understanding the Request Line

    Fiddler’s Inspectors have the choice of displaying either the relative or absolute URL in the Request Line. Displaying the absolute URL simplifies request tampering, while displaying only the relative path more closely replicates what servers actually receive.
    February 13, 2013
  • .NET

    Fiddler and Modern TLS Versions

    Recently, a Fiddler user contacted me to note that they discovered a client/server application which failed when the TLS version 1.1 option is enabled in Internet Explorer’s Advanced settings. They were surprised to find that when they attempted to use Fiddler to debug the communication, the connection was instead successful.
    February 11, 2013
  • .NET

    Announcing Fiddler 2.4.3 Beta

    Yesterday, an updated Fiddler Beta was released, targeting .NET2 or .NET4. This update contains the usual set of bug fixes as well as a number of small features that I hope you’ll find useful.
    February 08, 2013