Troubleshoot VS2013 WebApi with Fiddler

If you run client code in VS to test against a webapi in VS2013’s IIS Express, Fiddler does not see the traffic, because you are using “http://localhost:8080”.

The work around is to use “http://machinename:8080”.  But that won’t work with IIS Express; you can the error 400 saying invalid hostname.

So the work around is to modify the applicationhost file. 

  1. Find the IIS Express in your system tray. 
  2. Right click on it and select ‘Show All Applications’
  3. Select your site name.  Don’t click on the URL.
  4. Click on the “Config:” link.
  5. image
  6. Add a binding for your machine hostname:
  7. Restart VS 2013 (run as admin).


One can “add urlacl” to avoid the need to run VS2013 in admin.



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