Over the last 48 hours or so I've been asked a number of times about the tools I use when testing a sites performance. I thought it'd be frugal to have a link to point people at with a little explanation rather than a bombardment of 140 characters.
Web Page Test
This is the tool I often go to first. It allows you to enter an URL, decided where you want to test in the world and in what browser. This then tests the site (upto 9 times) and gives you several results to glean information from including a traffic light system of what you’re doing right, ok at or completely wrong.
This site combines two great tools into one nice package. Adding your URL runs the test through both Google’s PageSpeed and Yahoo’s YSlow resulting in a percentage score for both with pointers as to what needs doing in underneath. This is the tool I often tweet a screengrab from.
This is a great tool that just allows you to test a sites performance on a mobile device which is a great way to see how much data is being pushed to that pocket computer you've got in your hand.
These tools give you results in what you can do better most of which I’ve mentioned in a previous post.
If you’re really interested in web performance as a developer (and you really should be) then here’s a couple of books I’d highly recommend.
Web Performance by Andy Davies Available now as an eBook from Five Simple Steps
High Performance Browser Networking by Ilya Grigorik Available freely online, as an eBook or a paperback