This will tell you how many files were loaded, how long each one took, and the order in which they load. This will help you pinpoint the sources that are slowing your page load times.
YSlow is a tester built into Firebug. It will analyze your page and give it a grade based on industry standard practices. The first time you run this, you will get a bad grade, and all things may seem a bit overwhelming. Here are some areas to concentrate on:
- Compress components with gzip: Most web servers can compress responses. This makes for smaller files, and smaller files load faster.
- Use a Content Delivery Network (CDN): If you web server is serving up dynamic web pages, it does a lot of work to do that (reading and setting cookies, etc.). Most web servers are set up to only allow two connections per client. So if you are serving static content (like images, CSS files, etc.) from the same place, this adds work and creates a bottleneck. By using a CDN, you can offload those requests, reducing the strain on you web servers. The static files will then load faster and your dynamic content loads faster, too. For more info on CDN, look here: http://en.wikipedia.org/wiki/Content_delivery_network.
Step Two: Address – After finding the issues in your audit, this is where you actually pick which things to fix and then fix them. Some may be as simple as having IT enable features on your web server, but others can be more involved, such as publishing to a CDN. So choose your battles, and once your done…
Step 3: Repeat - Web load time optimization is not a “set it and forget it” thing. As your website changes and technologies change, there is always room for improvement. The best thing you can do is stay on top of it.