Speed Update: Mobile page speed will be a ranking factor on Google starting in July
Google announced today the “Speed Update." The Speed Update will "affect pages that deliver the slowest experience to users." It will start in July 2018, when page speed will be a ranking factor for Google mobile searches.
Google says this Speed Update will only affect a small percentage of queries, as the intent of the search query is still a very strong signal, so a slow page may still rank highly if it has great, relevant content.
(...) In this example, since users from Search would be seeing an AMP page, the speed of the AMP page would be taken into account. However, if a page built with AMP provides a slow experience to users, it may also rank lower in the results.
— John ☆.o(≧▽≦)o.☆ (@JohnMu) 17 de janeiro de 2018
https://platform.twitter.com/widgets.jsGoogle clarified after that AMP pages will also be affected by the Speed Update.
How to evaluate a page performance
Chrome User Experience Report
A public dataset of key user experience metrics for popular destinations on the web, as experienced by Chrome users under real-world conditions.
Lighthouse
An automated tool and a part of Chrome Developer Tools for auditing the quality (performance, accessibility, and more) of web pages.
PageSpeed Insights
A tool that indicates how well a page performs on the Chrome UX Report and suggests performance optimizations.