Website Running Slow? But Y?

Website slowness can be caused by a number of factors. Such factors include things like large images, poor server performance, embedded code (such as CSS and Java Script), too many HTTP requests, etc... So how do you pin it down? Why is it running so slow? A new tool from Yahoo! - YSlow makes it easy.

YSlow is a free add-on to FireFox (actually it's an add-on to Firebug which is an add-on to Firefox, but that's just semantics). You can run it on any page of a website that loads and it will provide an analysis of how that page loaded, and provide recommendations on what can be improved.

The core of YSlow's analysis is based on the following 13 rules that are key to improving web page performance:

1. Make Fewer HTTP Requests
2. Use a Content Delivery Network
3. Add an Expires Header
4. Gzip Components
5. Put CSS at the Top
6. Move Scripts to the Bottom
7. Avoid CSS Expressions
8. Make JavaScript and CSS External
9. Reduce DNS Lookups
10. Minify JavaScript
11. Avoid Redirects
12. Remove Duplicate Scripts
13. Configure ETags

YSlow can be downloaded here. It's a great tool, and has a lot of great information.