Website loading time debugging (what happens on the wire when you browse?)

One of my responsibilities is optimizing page loading time. There are some very useful tools on the web that help understand where are bottlenecks.

Firefox addons like Firebug with Yslow and Tamperdata are the most important and easy to use tools for every web developer.

On the other hand I see a lack of a tool that is more related to networking. It's fine that yslow can suggest me that caching headers are broken, but how can I test if a content is really cached.

I would like to see a tool that looks more or less like Firebug networking tab, but shows what is really going on on the wire. I would like to know all "If-not-modified" requests or if "Etags" are used. There is also tcp/ip layer that is sometimes forgotten. Are "Keep-alives" used, is establishing tcp/ip connection fast?

That's why I'm thinking of a new tool, nothing revolutionary, just useful tool for me. I'm currently writing the proof of concept. Sample screenshot from my work:

1 comment:

zuborg said...

Not sure TCP/IP layer information is useful. It highly varies from user to user.

I'll recommend you to take a look at this free online performance testing tool - http://Site-Perf.com/

It's very detailed and accurate, supports a lot of features like Keep-Alive and HTTP-compression, and shows nice loading chart so you can easily spot bottlenecks.

Also useful feature is that this tool can measure quality of internet link of your server.