Below is a comparison of a client's new opening (HOME) page vs. the original one. Note the difference of Google's PageSpeed Test results.
 

Note that both pages are very similiar, however, the new page passes Google's PageSpeed Test.

Slow load speed (see results below)
BEFORE SEO

Google PageSpeed Test Results

Google Speed Test

Fast load speed (see results below)
AFTER SEO

Google PageSpeed Test Results

Google Speed Test

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.