提升网站性能最佳实践

The Exceptional Performance team has identified a number of best practices for making web pages fast. The list includes 35 best practices divided into 7 categories.

01.Minimize HTTP Requests---减少http请求

1. simplify the page's design.
   2.Combined files
   3.Image maps
   4.CSS Sprites
   5.Inline images---are not yet supported across all major browsers.

   02.Use a Content Delivery Network---利用内容分发网络

   请记住，最终用户响应时间的80-90％用于下载页面中的所有组件：图像，样式表，脚本，Flash等。这是性能黄金规则。 而不是开始重新设计您的应用程序架构的艰巨任务，最好先分散您的静态内容。 这不仅实现了响应时间的更大减少，但是由于内容交付网络更容易。

   03.Add an Expires or a Cache-Control Header---添加过期或Cache-Control头

   Browsers (and proxies) use a cache to reduce the number and size of HTTP requests, making web pages load faster.

   04.Gzip Components---Gzip组件

05.Put Stylesheets at the Top---样式单置顶

06.Put Scripts at the Bottom---脚本置底

07.Avoid CSS Expressions---避免css表达式

08.Make JavaScript and CSS External---外置js和css

09.Reduce DNS Lookups---减少DNS查找

10.Minify JavaScript and CSS---缩小js，css

11.Avoid Redirects---避免重定向

12.Remove Duplicate Scripts---移除重复脚本

13.Configure ETags---配置ETages

14.Make Ajax Cacheable---让ajax可缓存

15.Flush the Buffer Early---尽早清理缓存

16.Use GET for AJAX Requests---利用GET做ajax请求

17.Post-load Components---后加载组件

18.Preload Components---前加载组件

19.Reduce the Number of DOM Elements---减少DOM元素数量

20.Split Components Across Domains----跨域分割组件

21.Minimize the Number of iframes---减少iframs数量

22.No 404s

23.Reduce Cookie Size

24.Use Cookie-free Domains for Components

25.Minimize DOM Access

26.Develop Smart Event Handlers

27.Choose <link> over @import

28.Avoid Filters

29.Optimize Images

30.Optimize CSS Sprites

31.Don't Scale Images in HTML

31.Make favicon.ico Small and Cacheable

33.Keep Components under 25K

34.Pack Components into a Multipart Document

35.Avoid Empty Image src