First of all, Pagespeed is a website optimization tool based on the Firefox Firebug plug-in released by Google after announcing that it will include website speed in the PR evaluation criteria. It can automatically analyze page content and provide very detailed optimization suggestions. Currently, it is an experimental tool in Webmaster tools. You can check the speed evaluation of your website in the Webmaster tools' lab menu.
Click Analyze Performance to analyze the current page.
After analyzing the page, expand the Optimize images project and you can see Pagespeed's optimization suggestions for all pictures on the current page. Google recommends using PNG format images, because PNG format can compress images with relatively small capacity lossless capacity. In fact, the PNG format is not smaller than the GIF format with the same content in any case, but the PNG format supports transparency much better than GIF. For the solution to the poor support for transparent PNG in IE6, you can search online, here is not Say more.
Pagespeed has counted how much transmission bandwidth will be reduced after all pictures on the page are optimized according to the optimization suggestions, and has calculated and compared the optimization effect of each picture separately. It is really detailed. Click on the compressed version, Firefox will open the optimized picture with a new tab. You can replace the picture you used first with this picture, save website bandwidth overhead, and speed up the opening of the web page.
Optimize JS and CSS
Expand the Miniify JavaScript and Miniify CSS projects to see the optimization suggestions for the website JavaScript and CSS
As we all know, JavaScript and CSS mainly achieve optimization results through the size of external link files. Pagespeed's suggestion is to use YUI compression and provide several online compression tools. But with Pagespeed, we don’t need to use those tools. Clicking on the minified version can immediately obtain the compressed JS and CSS files to replace the original file!
postscript
The introduction to the use of Pagespeed is here, and more usage methods are still to be explored. Changes in Google's PR evaluation rules can also reflect that website speed is a very important link in website optimization.