Chrome User Experience Report
The Chrome User Experience Report provides user experience metrics for how real-world Chrome users experience popular destinations on the web.

Methodology
The Chrome User Experience Report is powered by real user measurement of key user experience metrics across the public web, aggregated from users who have opted-in to syncing their browsing history, have not set up a Sync passphrase, and have usage statistic reporting enabled. The resulting data is made available via:

PageSpeed Insights, which provides URL-level user experience metrics for popular URLs that are known by Google’s web crawlers.

Public Google BigQuery project, which aggregates user experience metrics by origin, for all origins that are known by Google’s web crawlers, and split across multiple dimensions.