About Google PageSpeed Insights
Page Speed Insights measures the performance of a page for mobile devices and desktop devices. It fetches the url twice, once with a mobile user-agent, and once with a desktop-user agent.
The PageSpeed Score ranges from 0 to 100 points. A higher score is better and a score of 85 or above indicates that the page is performing well. Please note that PageSpeed Insights is being continually improved by Google and so the score will change as they add new rules or improve their analysis.