Monitoring HTTP Traffic

Over the past week or so, I’ve had a few people ask me questions that end up relating to HTTP traffic (usually ASP.NET-related). If you’ve never actually watched the traffic between your client and the remote server, you’re missing out on a lot of great insight. Two of the questions related to ASP.NET ViewState and bandwidth usage, and the other related to Web Service requests. I used to recommend a freely available tool called ProxyTrace (which has served me well for many years), but I’ve recently come to like Fiddler, which is also free. Although you can get a lot of this information by running NetMon, these two tools are targeted to HTTP, so they’re able to parse and display the traffic in a much more readable format. If you do Web Services or are just generally curious about what ASP.NET (or any site for that matter) is sending over the transport, check out these tools.