To learn more about the data in the Mobile Leaderboard visit the Chrome User Experience Report (CrUX).

Speed and Ranking: No single metric perfectly captures mobile site speed and user experience. As such, the ranking methodology is based on a combination of three metrics as reported across mobile devices by the CrUX Report: First Contentful Paint, DomContentLoaded and Onload. The site speed metric shows the 90th percentile of First Contentful Paint from the CrUX report. However, since rank is based on multiple metrics rather than on First Contentful Paint alone, sites with slower First Contentful Paint times may rank higher than sites with faster First Contentful Paint times.

Included Sites: The Speed Scorecard covers a subset of sites from the CrUX Report which provides speed data for popular URLs that are known by Google's web crawlers.