Fiddler2 includes the ability to capture web traffic (including AJAX requests) for later playback with the Visual Studio Web Test product.
- Capture traffic from your web application.
- Click File > Export Sessions > All Sessions.
- Click Visual Studio WebTest.
- Note: You must have a Visual Studio 2005 or later Team System product installed to load the .WebTest file.
To replay a WebTest:
- Click File > New project.
- Expand Visual C# or Visual Basic.
- Click the Test node.
- Click Test Project in the template pane.
Please see https://blogs.msdn.com/slumley/pages/how-to-debug-a-web-test.aspx for information on how to troubleshoot problems with WebTests.