How to configure Fiddler to listen to localhost?

Solution 1:

By simply adding fiddler to the url

http://localhost.fiddler:8081/

Traffic is routed through fiddler and therefore being displayed on fiddler.

Solution 2:

Add a dot . after the localhost.

For example if you had http://localhost:24448/HomePage.aspx

Change it to http://localhost.:24448/HomePage.aspx

Internet Explorer is bypassing the proxy server for "localhost". With the dot, the "localhost" check in the domain name fails.

Solution 3:

.NET and Internet Explorer don't send requests for localhost through any proxies, so they don't come up on Fiddler.

Many alternatives are available

Use your machine name instead of localhost. Using Firefox (with the fiddler add-on installed) to make the request. Use http://ipv4.fiddler instead of localhost.

For more info http://www.fiddler2.com/Fiddler/help/hookup.asp

Solution 4:

try putting your machine name/IP address instead of 'localhost' into URL. Works for me...

Solution 5:

Rather than configure the application server and client to use another domain, you may want to configure the client application to use a proxy. Fiddler also creates a proxy you can use, logging all traffic. Rick Strahl blogged about using this in .NET Apps, I am always misplacing this blog post, so let me link it here: http://weblog.west-wind.com/posts/2008/Mar/14/Debugging-Http-or-Web-Services-Calls-from-ASPNET-with-Fiddler.

To be brief, the app.config change is:

<system.net>
  <defaultProxy>
    <proxy  proxyaddress="http://127.0.0.1:8888" />      
  </defaultProxy>
</system.net>