1. Get Fiddler
Download Fiddler 

2. Set-up Fiddler
Start Fiddler then open the Tools > Fiddler Options... window


and in the Connections tab, ensure:

• "Allow remote computers to connect" is checked.
• "Act as system proxy on startup" is checked.
• Note or change what port is set (eg. 8888).

Once you've saved those settings you need to stop and re-start Fiddler.

3. Ensure Fiddler is 'listening'
Once Fiddler has re-started, verify that the Capture Traffic menuitem is ticked.


4. Check the 'listening' IP
You need to know your computer's wireless-network IP address to configure the iPhone. This screenshots shows the Command Prompt > ipconfig output:


5. Set-up iPhone Settings
With the computer IP address and Fiddler port, go to your iPhone's Wifi Settings and scroll down to the HTTP Proxy, choose Manual and input the Fiddler proxy info:

(remember to switch back to Off when you're done)

6. 'sniff' away
If everything has been setup right, anything you do in Safari or other internet based applications will be logged in the Fiddler window.


It's extremely useful for testing/debugging - have fun!