Cloudflare is open-sourcing the BEACON dataset, making billions of anonymized Real User Monitoring (RUM) performance records publicly available on Google BigQuery.

W3C Real User Monitoring Community Group (RUMCG)

How the CrUX 28-day rolling window actually works, what each source publishes, and why p75 takes so long to move even though the data is only two days old.

An interactive field guide to the Chrome DevTools Performance panel: waterfall, flame chart, LCP, CLS, INP, and the Insights panel.

Core Web Vitals data from ten leading online retailers reveals that "good" for Google may not be good enough for your users or your business.

Try out the Container Timing performance measurement API in origin trial from Chrome 148

Does it feel like the first few months of this year have gone fast, or is it just me? There's been a lot happening in the accessibility space this year already.

At Squarespace, many of our core products are built on web standards, and our engineers are constantly pushing the boundaries of the web’s capabilities. Occasionally, those boundaries reveal a limitat...

In a competitive market, page speed is as important as your design and content.

In this episode, Paul Calvano dives deep into querying the HTTP Archive dataset to uncover web trends, while Tammy Everts breaks down the "Performance Plateau", explaining why identifying your specifi...

Learn about the features included in Interop 2026.

YouTube video by Dave HJ

Support our St. Paul Public Schools Community - HIGHLAND PARK MIDDLE SCHOOL PARENT SOLIDARITY NETWORK - Cheddar Up. Collect online payments for events and fundraisers with Cheddar Up.

Enshittification isn't cliché, it's simply pervasive. Browsers being launched by AI companies will, undoubtedly, follow the same playbook we've seen over and over again.

performance.now() 2024 was the year we officially launched the W3 RUM Community Group. The idea to form a community group around real user monitoring (RUM) came from the desire to come together as ven...

ALT: muppet fozzie bear is singing into a microphone while wearing a hat and tie .

Like many people in the web industry I’ve been keeping an eye on the “state of AI” and what it means for my job, and my day to day life. To…

PixelPalooza will explore all the best practices we, as developers, can leverage media like images, video, audio and documents across our sites and applications.

A11y Pulse: Automated accessibility testing for your website. Improve your site's accessibility and compliance with ease.

Released November 4, 2025 — 26.2 beta (20623.1.12)