GeekFindr: YSlow, find out what’s slowing down your site
Scott pointed out YSlow to me some weeks ago and I’ve been using it every now and again. It’s a Firebug extension that grades you on how well you follow Yahoo’s 13 Rules for a High Performance Website.
Once you’ve added YSlow in you go to the site you want to profile and turn on Firebug (I generally keep Firebug turned off but will turn it on for a specific site when I want to use it). YSlow gives you a little bar as it goes through the site and loads all the components in and then it grades you (A-F) on each of the 13 rules. Anywhere that doesn’t get an A gets a little turndown arrow which will give you more details on what exactly it was that was slowing you down.
If you click on the stats cache you can see the difference between a first time view and a view with things that have been cached, this is pretty interesting and may give you some insight into trying to get more static files cachable. I like the “Printable View” under the tools tab that will show you all expanded out kind of everything YSlow has discovered about the site you’re profiling.
The catch is that this is Yahoo telling you how to make your site optimal. Yahoo, it turns out, is pretty different than almost every other site out there because it’s so big. So, I think a lot of the suggestions they make are not for most people, for instance I don’t really expect that I will ever use a Content Delivery Network for this blog, I suspect that even most of my clients would never go to these lengths. It also really hates the little widgets and beacons that so many sites use (i.e. Google Analytics, Feedburner tracking, etc…) - again it may be fine for Yahoo, but for a lot of us we need and like these external services.
I came across Coding Horror’s in depth explanation about why these are not all actionable items for most websites - if you are using YSlow you should read that article. Most people will see what YSlow tells them intuitively understand the lengths that they are willing to go to to optimize their site. It is well worth checking out - some tips could really prove invaluable, so give it a shot and see how YSlow grades your sites.
