ALL GOOGLE TOOL TO MONITOR YOUR BLOG OR WEBSITE

• Monitor your site's performance and optimize load times. Google's goal is to provide users with the most relevant results and a great user experience. Fast sites increase user satisfaction and improve the overall quality of the web (especially for those users with slow Internet connections), and we hope that as webmasters improve their sites, the overall speed of the web will improve.
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  Google strongly recommends that all webmasters regularly monitor site performance using Page Speed, YSlow, WebPagetest, or other tools. For more information, tools, and resources, see Let's Make The Web Faster. In addition, the Site Performance tool in Webmaster Tools shows the speed of your website as experienced by users around the world.