How do I display localhost traffic in Fiddler while debugging an ASP.NET application?
try using this:
http://ipv4.fiddler/folder
instead of
http://localhost/folder
this also works with ports
http://ipv4.fiddler:12345/folder
Here is link to fiddler documentation
http://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/MonitorLocalTraffic