Page Speed是個Firefox擴充套件「Firebug」的外掛程式，他的主要功能就是用來測試與衡
量你指定的網頁執行效能，看看哪些地方還可以微調或改善，讓你的網站開啟速度可以更
快、耗用更少的網路頻寬並強化網站運作效能。
量你指定的網頁執行效能，看看哪些地方還可以微調或改善，讓你的網站開啟速度可以更
快、耗用更少的網路頻寬並強化網站運作效能。
Page Speed只是個建議工具，意思是他只會跟你說哪些地方可能有問題，哪些地方可以再改
善，只是提供建議而已並不會幫你改到好。如果你之前就已經用過Firebug來測試網頁的話，
Google Page Speed可以提供更多、更具體的改善細節與最佳化方向，讓我們可以直接針對
這些問題做處理。
In Chrome, PageSpeed Insights extension runs in theChrome Developer Tools.
Supports Mac OS X (x86), Linux (x86 and x86-64), and Windows (XP and up)
Run PageSpeed Insights against your web pages
Follow the instructions to use PageSpeed Insights in Chrome or Firefox. When you visit a web page, open PageSpeed Insights and click "Analyze Performance" to get a performance report for that page. PageSpeed will present you with a set of rules and recommendations. Before you start changing the scripts and resources on your pages, press on the rule to understand what it is pointing out and its background.
Get familiar with the tool. There are a number of features that are easily accessible from the menus of the extension. In particular, for the Firefox extension, in the top tab called "PageSpeed", a caret next to the text gives you the ability to set preferences for how PageSpeed runs and where it saves optimized resources.