In my audits, reading the Performance profile is where people get stuck: the flame chart and waterfall look like noise at first I built an interactive guide to make them click, every figure is interactive, plus LCP, CLS, INP and the Insights panel perf.reviews/profile-guide #WebPerf #DevTools

Reading a Performance Profile: Field Guide

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

perf.reviews

If you make websites for a living, stop what you're doing and read this research by @tammyeverts.com; it shows what many of us have been saying for a long time: even if there is such a thing as "fast enough", it's generally *much* faster than you are targeting: embrace.io/blog/research-co…

New research: The Core Web Vitals thresholds you trust might be wrong for your site

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.

embrace.io

There's a new #webperf measurement API in the works! Check out this post looking at the work @jason-williams.co.uk and @jdapena.bsky.social have been putting into there Container Timing—available as an origin trail from Chrome 148 (rolling out next week). developer.chrome.com/blog/contain...

Container Timing origin trial  |  Blog  |  Chrome for Developers

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

developer.chrome.com

Had a delightful session today. A great conversation was had w/ @jdapena.bsky.social of @igalia.com about the work being done w/ container timing in Chrome. Both @jason-williams.co.uk + @andydavies.me got mentions. 🙃 This should be published soon. Thx to all who joined in!

It feels like it's been a lifetime since I wrote content instead of code, but I'm finally back at it! I put together this March newsletter for A11y Pulse, covering what we shipped last month: www.a11ypulse.com/blog/newslet...

Okay guys they've gone behind the Moon so it's time for us to put our ape masks on This is going to be HILARIOUS

New on the Squarespace Engineering Blog! Squarespace & Web Standards: How We Helped Bring HTML Video & Audio Lazy-Loading to Today’s Browsers. I'm real proud of the teamwork that went into this. Stay tuned for part 2 next week, which will cover dev best practices for using this new HTML standard.

Squarespace & Web Standards: How We Helped Bring HTML Video & Audio Lazy Loading to Today’s Browsers — Squarespace Engineering Blog

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...

engineering.squarespace.com

p75 and p90 JavaScript bytes on the web have exploded since May, 2025—easily the largest 10 month period based on HTTP Archive data since 2023. The long-tail is getting worse, very quickly. Gemini, what happened in May 2025?

Jim Acosta testified before Congress today warning that a pending merger could hand CNN to Trump-aligned billionaires. He’s never stopped speaking truth to power, even when it cost him. We’re grateful someone is still saying it out loud. Share if you believe in a free press. @jimacosta.bsky.social

Southwest Airlines Begins Assigning Chores https://theonion.com/southwest-airlines-begins-assigning-chores/

How dare her!! 🧐🤨 "When people like Kamala Harris send our sons and daughters, our young people, to fight in stupid wars, it is the young generation that carries the burden of that. We're gonna stop sending our young people to far away lands. We are not the policemen of the world."

A slow UX affects people’s perception of three important brand elements that are completely unrelated to page speed: content, design, and usability. Here's why that takeaway is relevant in an increasingly competition online landscape 👉 www.speedcurve.com/blog/brand-p... #webperf #ux #pagespeed

SpeedCurve | The speed of trust: How slow pages hurt your brand

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

speedcurve.com

So excited to be paired with @paulcalvano.bsky.social for this double-header on PerformanceObserver next week! Paul will take a deep dive into the HTTP Archive. Then I'll break down the "performance plateau" – why you need to know it and how to find it. performanceobserver.dev/events/episo...

Querying the HTTP Archive and finding your Performance Plateau | PerformanceObserver

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...

performanceobserver.dev

Ironic that England does No Kings better than we do

Will it be national news? Will it cause performative outrage? Will he be censured? Nope. Forgotten by tomorrow.

Shame about the lack of #webperf enhancements accepted into Interop 2026, particularly CLS which would have been really useful. But there are plenty of performance-adjacent improvements, mainly via CSS enhancements such as anchor positioning and scroll-driven animations: web.dev/blog/interop...

Interop 2026: Continuing to improve the web for developers  |  Blog  |  web.dev

Learn about the features included in Interop 2026.

web.dev

Country Singer, songwriter Charley Crockett well said......

Flashback to 2008 when John McCain shut down a racist line of questioning. I miss this Republican Party.

✨ SPDY STREAM 023 ✨ w/ @dbelson.com of @cloudflare.social, Head of Data and Insights. We are excited to welcome David in discussing the recently released @radar.cloudflare.com 2025 Year in Review! Join us! ✨ SPDY STREAM 023 ✨ 📆 Wed Feb 4th 2026 ⏰ 1pm EST, 10am PST 🔗 www.youtube.com/live/R-j3HrE...

Hi friends. Are you finding that suddenly armed gangs are roving your street deploying chemical weapons like it's candy at a parade? You can go to Menards or a hardware store and get the 3M chemical respirators. They are in the paint section. Smalls exist but they need to be ordered. Stay safe!

Ladies and gentlemen, the greatest American songwriter that no one remembers, Blaze Foley. Give him two minutes and he might change your life.

Blaze Foley - Clay Pigeons, rare Live

YouTube video by Dave HJ

youtube.com

For anyone wanting to support the people under attack in St. Paul here's a fundraiser being organized by people in the public schools to help directly with rent relief. This is a huge need, please share widely! ❤️‍🔥 my.cheddarup.com/c/support-ou...

Support our St. Paul Public Schools Community - Cheddar Up

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.

my.cheddarup.com

"Websites that work perfectly in traditional browsers may end up broken for actual accessibility tools. The web will fragment as sites must test against a growing number of AI browser agents with different requirements." www.coryd.dev/posts/2025/a...

AI browsers are straight out of the enshittification playbook • Cory Dransfeldt

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.

coryd.dev

This one got released rather quietly and I think could do with a bit more attention! Read about how to avoid caching performance penalties due to tracking query params and the like!

Stoyan Stefanov @stoyan.me · 8mo ago

Web Performance Calendar day 23 with @tunetheweb.com on configuring caches to ignore non-content-affecting URL parameters and reclaim performance. No more of this query string = cache miss nonsense. calendar.perfplanet.com/2025/fixing-...

Web Performance Calendar day 15 with @nicj.net, @cliffcrocker.bsky.social and @karlijnlowik.bsky.social Löwik presenting an update on W3's RUM Community Group and YOU calendar.perfplanet.com/2025/rumcg-a...

RUMCG - A year in review

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...

calendar.perfplanet.com

LCP and INP are now Baseline newly available /since they are now available in all major browsers! 🎉🥳🍾 Really, really, really curious to see what sort of new performance insights we’ll see as sites start to collect and look at the data! #CoreWebVitals

Jen Simmons@jensimmons.bsky.social · 8mo ago

Safari 26.2 is here with 65 features + 165 bug fixes — including field-sizing, Navigation API, Largest Contentful Paint, command & commandfor, CHIPS opt-in partitioned cookies, scrollend event, random(), WebGPU in WebXR, scrollbar-color, hidden=until-found and much more! webkit.org/blog/17640/w...

Since it was mentioned by @cliffcrocker.bsky.social on the @embrace.io x @speedcurve.com webinar: A reminder that Mike K of @cloudflare.social is my guest tomorrow to talk about TELESCOPE. Really excited for this one. Join us! 📆 Wed Dec 10th ⏰ 2pm EST 🔗 www.youtube.com/live/hhNFI_X...

Really excited for this. Telescope is so hot right now.

Henri Helvetica 🧑🏾‍🚀🇭🇹@henrihelvetica.bsky.social · 8mo ago

✨ SPDY STREAM 020 ✨ w/ Michael Kozicki of @cloudflare.social @cloudflare-dev.bsky.social Michael joins us to present Telescope: a cross-browser performance testing agent that automates page loads across browsers, collects data. Join us! 📆 Wed December 10th ⏰ 2pm EST 🎥 youtube.com/live/hhNFI_X...

I’ve been seeing a lot of AI talks and articles lately - I have no idea what’s going on but it has got me wondering about Performance and accessibility and I only have more questions. “People deserved a better web. Will AI be the one who gets it?” medium.com/@mandy.micha...

People deserved a better web. Will AI be the one who gets it?

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…

medium.com

#PixelPalooza is coming up this Thursday! This awesome FREE online event covers how to make sure all those helpful images and videos on your site don't hurt #webperf and #a11y. I'm joining @seancdavis.com to talk about the hidden cost of media on the web. Get your ticket 👉 cfe.dev/events/pixel...

PixelPalooza 2025

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

cfe.dev