Traffic Analyzers

Many problems can be resolved by watching the traffic between the browser and the server. While IDE's and web add-ons analyze traffic, the following standalone programs are more heavy-duty. If you are having any problems with XHR or with js/html/css/jpg files not loading as you would expect, this is often the best way to diagnose them quickly. Also if you are having problems with required files not loading then this is a good starting point to find out why.

• Fiddler is a fantastic HTTP header and content inspector for Windows. It understands HTTP and presents the information very clearly (once you get used to its slightly quirky interface). Well integrated with IE, but work s with any browser. With FF a useful extension to help use Fiddler is the Switch Proxy extension (scroll down that page to find it).
• Wireshark (formerly Ethereal) is great for sniffing all kinds of network traffic.