The Chrome UX Report, almost universally known as CrUX, is the data source that underpins Google’s real-user performance metrics. It’s a dataset that Google publishes publicly, collecting performance measurements from real Chrome users who’ve opted in to sharing their browsing data. The data covers Core Web Vitals metrics including LCP, INP, and CLS, broken down by connection type, device category, and form factor. When you see Field Data in PageSpeed Insights or the Core Web Vitals report in Search Console, you’re looking at CrUX data.
As a standalone tool, CrUX is primarily for data professionals and developers who want to query the raw dataset directly. It’s available via Google BigQuery, where you can write SQL queries to pull performance data for any URL or origin in the dataset. This opens up analysis that consumer tools simply can’t offer: you could, for example, compare the real-user LCP distribution of your site against 50 of your closest competitors, or analyse how your performance varies by country or connection type.
I find CrUX most useful for competitive benchmarking. There are also several free dashboards built on top of the dataset, including the CrUX Dashboard on Looker Studio, which gives you a pre-built visualisation of your origin’s Core Web Vitals history without needing to write any SQL. If you’re comfortable with data tools, the raw BigQuery access is incredibly powerful. If you’re not, the consumer tools like PageSpeed Insights that wrap CrUX data are a more practical starting point. Either way, understanding what CrUX is and where the field data comes from makes you a more effective performance analyst.