What is the Chrome User Experience report (CrUX)?

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The Google Chrome User Experience Report, or CrUX report, provides real user measurements from Chrome users who meet Google's eligibility settings. It is field data: a view of how real users experienced a page or origin, not a lab test run from one machine.

The statistics are updated daily and report a rolling 28-day average of the last 28 days.

For the fuller guide, see what is the Chrome UX Report and why should you care?. You can also use Peakhour's website speed comparison tool to compare Core Web Vitals for your domain and competitor domains you choose.

Core Web Vitals in CrUX

First Contentful Paint: When the browser first renders any text or image (including background images)

Largest Contentful Paint: Marks the time when the page's main content has likely loaded.

Interaction to Next Paint: Measures the responsiveness of a page to user input, eg a key press or a mouse click.

Cumulative Layout Shift: Measures visual stability of a page, ie does content move as the page loads.

These metrics are defined in Google's Web Vitals

Report dimensions

The metrics can be viewed by device type (Phone, Tablet, Desktop), connection speed, (4G, 3G, 2G) and are broken down by the proportion of visitors that match the 'good', 'needs improvement' and 'poor' guidelines. The report also shows the 75th percentile score for the website which is used to determine whether a website actually passes the recommendations.

Why CrUX matters

CrUX data feeds the public Core Web Vitals view used by tools such as PageSpeed Insights and Search Console. The useful operational point is simple: if your 75th percentile field data is poor, real users are seeing the problem and search visibility can be affected.

Where to view CrUX

Data is available via PageSpeed Insights, Google's BigQuery project, Search Console, Looker Studio dashboards, and Google's CrUX API.

Unless your website is reasonably busy it won't appear in the report.

For diagnosis, pair CrUX with lab tools such as WebPageTest. CrUX tells you whether real users are affected. Lab tools help explain redirects, cache misses, slow third parties, image weight, and server timing.