PageSpeed Insights

PageSpeed Insights is an easy-to-use high-level web performance testing tool. It's a free service run by Google, available at developers.google.com/speed/pagespeed/insights.

It offers a quick-and-dirty heuristic analysis of your web pages, based on categories of performance best-practices that your site is scored against. It will also offer suggestions such as minifying text content and compressing images where appropriate.

While it will probably be able to demonstrate that your AMP pages perform better than your non-AMP pages, it doesn't offer the same degree of insight as some of the other tools, and it isn't good at handling the subtleties of performance, sometimes scoring fast AMP pages poorly.

For this reason, it's not recommended to rely solely on PageSpeed Insights to determine the performance of your web pages.