How do I get Fiddler to stop ignoring traffic to localhost?

Question

When using Fiddler to monitor HTTP Requests & Responses in Internet Explorer it ignores all traffic directed to http://localhost.

Answer 1

Go to Tools, Fiddler Options ..., select the Connections tab, then make sure Monitor all connections is ticked. Like Antony Scott said, but also make sure that the "Web Sessions" pane is set to "Capturing" and [ "Web Browsers" OR "All Processes" ]. Looks like the default is "Non-Browser".

Answer 2

Fiddler's website addresses this question directly.

There are several suggested workarounds, but the most straightforward is simply to use the machine name rather than "localhost" or "127.0.0.1":

http://machinename/mytestpage.aspx

Answer 3

To get Fiddler to capture traffic when you are debugging on local host, after you hit F5 to begin degugging change the address so that localhost has a "." after it.

For instance, you start debugging and the you have the following URL in the Address bar:

http://localhost:49573/Default.aspx

Change it to:

http://localhost.:49573/Default.aspx

Hit enter and Fidder will start picking up your traffic.

Answer 4

Using Fiddler v4.6 and the default configuration could not see any traffic from 'localhost'. Tried many suggestions here but nothing worked.

Enabled Help -> Troubleshot and could see many more requests. Sessions were marked in a strike-through font and reason given was 'Hidden due to Status Bar> Process Filter.'

Found this reply from Eric Lawrence to person having same problem http://www.telerik.com/forums/fiddler-not-capturing-ios-traffic-even-though-echo-service-works

basically what to do is: Look at the Status Bar across the bottom of the Fiddler window, the second little "tray" in that bar probably says something like "Web Browsers." Click that and then change to "All Processes."

Answer 5

Fiddler v4.5.1.0 will allow you to go to replace "localhost" with "localhost.fiddler", and present localhost as the host name for the receiving server running on your machine.

This avoids "host not recognised" errors when connecting to WCF services with the built in web server that visual studio uses.

i.e. Instead of http://localhost:51900/service.wcf you can use http://localhost.fiddler:51900/service.wcf

Answer 6

Internet Explorer has a new feature since IE9 RC: adding <-loopback> to the proxy bypass list causes WinInet (the network library used by IE) to send requests destined for localhost and 127.0.0.1 through the defined proxy.

Here's the original announcement by @EricLaw: http://blogs.msdn.com/b/fiddler/archive/2011/02/10/fiddler-is-better-with-internet-explorer-9.aspx