First, let me explain. Pagespeed is a website optimization tool based on the Firefox Firebug plug-in released after Google announced that it would include website speed in the PR evaluation criteria. It can automatically analyze page content and provide very detailed optimization suggestions. It is currently an experimental tool in Webmaster tools . You can check the speed evaluation of your website in the lab menu of Webmaster tools.
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 images on the current page. Google recommends using images in PNG format because the PNG format can losslessly compress images with a smaller capacity. In fact, the PNG format is not in any case smaller than the GIF format with the same content, but the PNG format supports transparency much better than GIF. For solutions to IE6's poor support for transparent PNGs, you can search online, but there is no solution here. Too much to say.
Pagespeed has calculated how much transmission bandwidth will be reduced after optimizing all the pictures on the page according to the optimization suggestions, and has calculated and compared the optimization effect of each picture separately. It is really meticulous. Click compressed version, and Firefox will open the optimized image in a new tab. You can use this image to replace the previously used image, saving website bandwidth overhead and speeding up the opening of web pages.
Optimize JS and CSS
Expand the Minify JavaScript and Minify CSS projects to see optimization suggestions for website JavaScript and CSS.
As we all know, JavaScript and CSS are optimized mainly through the size of external link files. Pagespeed’s recommendation is to use YUI compression and provides several online compression tools. But with Pagespeed, we don’t need to use those tools. Click minified version to immediately get the compressed JS and CSS files to replace the original files!
postscript
The usage demonstration of Pagespeed is introduced here, more usage methods are yet to be explored. The changes in Google's evaluation rules for PR can also reflect that website speed is a very important part of website optimization.