How the Web Page Test tool is useful?

How the Web Page Test tool is useful?
Web Page Test is a tool for testing the speed and analyzing the performance of a given web page.
The test can be run from over 40 different locations and over 25 different browsers, including mobile. The tests performed grade your website from F to A depending on the overall performance of your website.
The analysis report provided by Web Page Speed includes six different sections: Summary Data, Performance Overview, Content Breakdown, Domains, and Screenshots. You can also go through the advanced features provided by Web Page Test, which include features like video capture, disabling JavaScript, ignoring SSL certificates, and spoofing user agent strings.