A dataset of real-world performance and user experience metrics for websites and web applications, the Chrome User Experience Report (CrUX) is maintained by Google based on data collected from millions of Chrome browser users. The dataset includes various performance metrics such as First Paint, First Contentful Paint (FCP), DOM Content Loaded, Largest Contentful Paint (LCP), Onload, Cumulative Layout Shift (CLS), First Input Delay (FID), and Interaction to Next Paint (INP). These metrics provide insights into how users perceive the performance of a website or web application, helping website owners and developers understand and optimize the user experience, particularly in terms of page load times and visual stability.
Performance Metrics
The CrUX dataset includes several key performance metrics:
- First Paint: The first key moment when the browser has started to render the page.
- First Contentful Paint (FCP): The time it takes to display the first content on the screen.
- DOM Content Loaded: The time it takes for the initial HTML document to completely load, without stylesheets, images, or subframes to finish loading.
- Largest Contentful Paint (LCP): The time it takes to display the largest content element on the screen.
- Onload: When the pages and their dependent resources have finished loading.
- Cumulative Layout Shift (CLS): A metric that measures the visual stability of a page by quantifying unexpected layout shifts.
- First Input Delay (FID): A measurement of load responsiveness when the user is trying to interact with the page.
- Interaction to Next Paint (INP): The latency of all interactions throughout the entire page lifecycle.
Tools and Integration
CrUX data is integrated into various tools and services developers use for performance analysis and optimization. One of the primary tools is the PageSpeed Insights tool, which provides a performance score and recommendations for improving web page speed and user experience. The data is also used in the Lighthouse auditing tool, which offers detailed performance metrics and suggestions for improving a website's performance. Web developers and site owners leverage CrUX data for benchmarking, monitoring, and making data-driven decisions to improve performance.
Privacy and Data Collection
CrUX data is anonymized and aggregated to ensure user privacy. The dataset encompasses a diverse range of users, offering insights into performance across various devices, network conditions, and geographic regions. If you have a sufficiently popular website, you can also see a historic view of your CrUX visibility.
