Fiddler is a tool that can capture and display HTTP traffic on a Windows PC, so it's great for debugging, testing and optimizing websites and programs that access the network. It can also act as a proxy and capture iPad traffic. Doing so lets you use Fiddler to debug or test your iPad's network activity. Fiddler's comprehensive HTTP decoding ability allows you to examine the contents of the traffic sent and received by your iPad in detail.
Set up Fiddler as a Proxy
Launch Fiddler by pressing the Windows key, typing "Fiddler" and pressing "Return."
Chose "Tools, " and then click "Fiddler Options...." Choose the "Connections" tab. Make sure the "Allow remote computers to connect option is selected." Note the port number in the "Fiddler listens on the port" text box. It's usually 8888.
Find the IP address of your PC. Open a command-line interface window by pressing the Windows key, typing "cmd" and then pressing "Enter." At the prompt, type "ipconfig" and press "Enter." Note the IP address of your PC, which will be displayed by the ipconfig command. Look for the entry labeled "IPv4 Address."
Set up Your iPad to Use a Proxy
Open the Settings app on your iPad and choose Wi-Fi. Tap the blue arrow next to the name of your wireless network.
Near the bottom of the screen under "HTTP Proxy" tap "Manual" and the proxy setup appears.
Type the IP address of the Windows PC and the port for the machine that is running Fiddler. Now whenever you use an app on your iPad that connects to the Internet on port 80, Fiddler will capture the traffic on the PC.
- Fiddler only captures HTTP traffic, so if the app you're monitoring (the Mail app, for example) uses a different port you won't see the traffic.
- Make sure that Fiddler capturing is turned on by choosing "File" and verifying there is a check mark next to "Capture Traffic."
- When you're done capturing traffic, make sure you turn off the HTTP proxy on your iPad.
- Make sure that the Windows Firewall isn't blocking traffic on the port that Fiddler uses to proxy external traffic.
- You can capture HTTPS traffic by enabling HTTPS decoding from the HTTPS tab on the "Fiddler Options" dialog box. Note that this uses man-in-the middle decryption, which will cause some apps -- notably App Store -- to fail.
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