Cloudflare opens its web performance data to everyone

Cloudflare published BEACON on 28 September 2026, an anonymised dataset built from billions of real-world performance measurements taken across 10,000 of the largest websites on its network. It covers every major browser engine, is updated daily in Google BigQuery, and reports all three Core Web Vitals — Largest Contentful Paint for loading, Cumulative Layout Shift for visual stability and Interaction to Next Paint for responsiveness.

The important difference from the public performance data developers already have is the shape of it. BEACON publishes full histograms rather than single averages, which means any percentile can be derived instead of stopping at the P75 figure that has become the default pass mark. That exposes the long tail of slow experiences that averages bury.

Safari's split personality

Cloudflare's own reading of the data is that WebKit, the only browser engine on iOS, performs best overall — but not everywhere. In 46 countries where WebKit accounts for more than 10 per cent of traffic, its Largest Contentful Paint, Interaction to Next Paint or both are at least 10 per cent worse than Blink-based browsers such as Chrome, Edge and Opera. In Cambodia, where WebKit carries 17.5 per cent of page views, its Largest Contentful Paint is 50 per cent worse than Blink's.

The dataset also carries domain industry classifications. Government and Politics, Health, and Safe for Kids rank as the strongest categories, while Ads, Religion and Weather typically perform worst. Breaking Largest Contentful Paint into sub-parts, Cloudflare found that downloading the resource — the image, font or video everyone assumes is the problem — contributes least to perceived load time. Discovering the largest element and unblocking its render are the bigger opportunities.

The same breakdown applied to Interaction to Next Paint shows JavaScript execution covering the longest period of slow interactions, with presentation time rising sharply alongside it, usually because of complex CSS layout recalculation. Cloudflare says it will add the sub-part metrics to its own Real User Monitoring dashboard in the coming weeks, and describes BEACON as expanding the community-led RUM Archive standard's footprint roughly 100-fold.

Our opinion

Chrome's User Experience Report has been the default public window onto real-world web performance for years, and its weakness has always been resolution: you get a percentile, not a distribution, and you get it for the sites Google chooses to sample. BEACON's value is not that it is bigger, it is that it is shaped differently. A histogram lets you ask how bad the worst decile is, which is the question anyone building for a market with old hardware actually needs answered.

The WebKit finding is the part worth sitting with. iOS Safari looks excellent in any global average, which is exactly why so many teams treat iPhone performance as solved and spend their optimisation budget on Android. A 50 per cent Largest Contentful Paint penalty in Cambodia, in a country where WebKit is nearly a fifth of traffic, is the kind of regional failure an aggregate hides completely. If a third of the world's mobile budget hardware is being served by a browser that degrades unevenly by market, developers have been optimising against a flattering number.