High Performance Web Sites, Part 2

In my first book, High Performance Web Sites, I presented 14 rules for making web pages faster. I’ve got some good news and some bad news. Bad news first: there are more than 14 things you have to do to speed up your pages. The good news is I’ve started another book that describes more best practices for web performance. The working title is High Performance Web Sites, Part 2. Here’s the set of rules I have so far:

  1. Split the initial payload
  2. Load scripts without blocking
  3. Don’t scatter scripts
  4. Split dominant content domains
  5. Make static content cookie-free
  6. Reduce cookie weight
  7. Minify CSS
  8. Optimize images
  9. Use iframes sparingly
  10. To www or not to www

As I finish chapters I’ll talk about my findings at conferences. My slides from Web 2.0 Expo last week contain information about the first three rules. In the future I’ll be speaking at Google I/O, Velocity, OSCON, and The Ajax Experience, so please come see me if you’re there. Also, I’ll write a blog post about each chapter. (Posts on Rules 1-3 are coming soon.)

The book should be out in early 2009. As I continue my research on web performance here at Google I’ll come up with another 5-10 rules to include. But I also wanted to ask you for suggested rules. What do you think is the performance killer for your web app? Better yet, what performance best practices have you discovered? For example, I think 3rd party rich media (Flash and JavaScript) ads are the long pole in the tent for many sites, and knowing the best way to embed widgets is growing more and more important. If you have a suggestion for a performance rule add it in a comment below and I’ll check it out.

OK, time to put the nose to the grindstone.