Fixing the URL params performance penalty. @tunetheweb.com introduced No-Vary-Search, a new HTTP header that helps browsers and CDNs ignore irrelevant query params and improve caching efficiency. For now, supported only in Chrome 141. #performance #http calendar.perfplanet.com/2025/fixing-...

Oh hey, come work with me! We're seeking an earlier-career front-end dev who is able to work in-office (multiple US locations). Check it out if you have interest and experience in: #designsystems #CSS #a11y #webcomponents adobe.design/jobs/job-pos...

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!

Good explanation of fetch priority!

Web Performance Calendar day 18 with Amrik Malhans on breaking down LCP to pinpoint what's slowing down the page exactly and where to focus your UX-optimizing efforts calendar.perfplanet.com/2025/the-ana...

What are your biggest complaints about using the web right now?

Answering some of your questions about what it means now LCP and INP are "Baseline Newly available" across all major browsers. Let me know if you have any more! web.dev/blog/lcp-and... #CoreWebVitals #webperf

Nice little tool, and interesting stats. www.madebyolof.com/bluesky-wrap... This year on Bluesky I wrote 202 posts and 669 replies. I received 4,016 likes, whereas 224 was from my most popular post, and apparently I love saying "use" and 🧵!

Speeding up CSS with compression dictionaries. @yoav.ws shows how combining critical and full CSS via compression dictionaries cuts bandwidth and accelerates page transitions. Works now in Chromium. #performance #css calendar.perfplanet.com/2025/how-to-...

Lazy loading out-of-viewport images can make the main content on your website load faster. ⬇️ Learn how in this video. www.youtube.com/watch?v=CPJf...

PSA: Our roadmap for 2026:

I like this write up. @piccalil.li is a file based "CMS" — infinitely more complex than cursor.com — and it's a nightmare to run because it's massive It gets a bit tiresome reading "you don't need X because of AI" stuff, so I'm glad folks like Sanity are rightly standing up to it.

The 2025 State of HTML survey is out 2025.stateofhtml.com And I love the opening stat — Lazy Loading FTW! Built-in, simple to use, attributes and elements are HTML's super power. And you can see that reflect in other attributes with the largest increase (details/summary, dialog, fetchpriority!)

It took a while (mainly due to the huge quantity of data collected on some questions!), but the #StateOfHTML 2025 survey results are now live! 2025.stateofhtml.com/en-US/ Big thanks to @lea.verou.me who not only designed the original survey back in 2023, but then came back this year to update it.

"The <time> element should actually do something" by Nolan Lawson nolanlawson.com/2025/12/14/t... Reminds me of the the recent session on @tantek.com.web.brid.gy's proposed <amount> at tpac. Maybe moz would experiment

Debunking the myth that every browser has its own set of extension APIs: youtu.be/PW2u2IZWjtk?...

If you’re using server-side AI models, you usually need an API key to call them. A couple of weeks back I made a video looking at how to handle that in a Chrome extension: youtu.be/pl4pz4nWa3w

🎙️LET'S GET READY TO RUMBLE! It's been one of DevTool's most requested features… weighing at eiiighty-five votes… 10 years in the making… entering the ring from Chrome 144… Heeeerre's: Individual request throttling!!! developer.chrome.com/blog/throttl... 🥊 It's a knockout! The crowd does wild! 👏🙌🎉🥳

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...

Out today: the Q4 release of the in progress Web Sustainability Guidelines. New filters, updated UX section, less overlap/duplication and more www.w3.org/TR/web-susta... Release notes: github.com/w3c/sustaina... hat tip to @alexdawsonuk.bsky.social and Rose Newell and everone else (see notes). 👏👏

Rob Reiner: I'm going to make a coming of age drama, a fantasy adventure story, a romantic comedy, a psychological horror and then a courtroom drama. Us: Across your entire career? Reiner: In a 6 year period. Us: That sounds- Reiner: -Each one will be arguably the best movie in that genre.

Once more for the folks in the back: accessibility is a human right. Your web standards godfather shares thoughts on a small atrocity.

ICYMI, some considerations for how to make CSS Carousels accessible: developer.chrome.com/blog/accessi...

"The author of the Smashing Magazine post may simply be taking Google at its word and that’s unfortunate for his credibility as well as the devs who read it." would love to have a chat! But not with people who directly hit below the belt. With all due respect: I believe in educating, not trolling.

> @amysiskind.com

If you ever wondered what those numbers after the listed bugs are: they’re Apple-internal bug tracker IDs. They’re not linked to anything because Feedback Assistant (née Radar) is Apple-internal, but there are ways to find the linked commit and public WebKit bug from it: www.bram.us/2025/12/13/f...

Web Performance Calendar day 13 with Yoav Weiss (@yoav.ws) showing us a clever and creative way to ship *only* critical/necessary CSS for each page type (home, search, etc) while also avoiding duplicate code in the CSS bundles. calendar.perfplanet.com/2025/how-to-...

Scroll-triggered animations are coming to Chrome early next year (we've been really excited about this one!) 🥳 Unlike scroll-driven animations (already in Chrome & Safari), this API introduces "timeline-trigger" and "animation-trigger" to start an animation within a specific range. Learn more ⬇️

Blink: Intent to Ship: Layout Instability API CSS Pixel Attribution

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

This is bound to end well… www.theguardian.com/us-news/2025...

Do you know about the developer-signals repo? If you want to see a feature supported across browsers, now you can go and upvote it, anytime github.com/web-platform...

Researchers have found two new vulnerabilities in React Server Components while attempting to exploit the patches last week. These are new issues, separate from the critical CVE last week. The patch for React2Shell remains effective for the Remote Code Execution exploit.

CSS text-decoration-inset landed in Firefox 146! Here's how it works:

Just published a polyfill for <input type="checkbox" switch>: github.com/tomayac/inpu.... Here's a quick demo: tomayac.github.io/input-switch.... A little proud of how this conditionally only loads when it's needed. Compare Chrome (above, needs the polyfill) and Safari (below, doesn't need it).

Good conference, which is well organised, based on my experience speaking there last year. Recommended.

Btw you don’t need to be a web spec author or work for a browser vendor to contribute to this. If you spot some incorrect data (either says it supports web it doesn’t, or says it doesn’t when it does) then open an issue — or better yet a PR! Make things better for everyone, including future you!!

The browser-compat-data project (used by MDN, caniuse, and tools) now has: 20,000 commits 1,123 contributors 465 releases 19,148 data entries That's what comprehensive web compat data looks like. And it takes well funded teams at @openwebdocs.org and @mozilla.org plus amazing contributors.

Not really thought about it until now but I’ve noticed I’m having to use ARIA less and less. And that’s a good thing. Accessible by default is a much better option. Even if it’s somewhat a pipe dream, the fact we’re make great strides towards that is fantastic.

On day 9 you discover dialog with @sjoy.lol #htmhellAdventCalendar htmhell.dev/adventcalend...

Urgh finally upgraded to iOS 26 and not loving it. Everything seems to just take up more space needlessly. And as for Liquid Glass — Liquid Pass more like! (I’m here all week, tip your server!)

“To restore decorum and professionalism to the Department’s written work products and abolish yet another wasteful DEIA program, the Department is returning to Times New Roman as its standard typeface,” #font #DEI #a11y #politics www.theguardian.com/us-news/2025...

Some of us have been waiting a loooong time for Temporal! 🥁

🚀 CSS Wrapped is out! We’re entering a world where CSS can increasingly handle logic, state, and complex interactions once reserved for JavaScript. It’s no longer just about styling documents, but about crafting dynamic, ergonomic, and robust applications. www.smashingmagazine.com/2025/12/stat...

Agree with a lot of this—even the comment about ours. Good case studies are good, but hard to produce! People's primary focus when doing web dev is not to produce the case studies. Or necessarily make all that data public even if they have it. So it often is a look back and produced after the fact.

This is just like...really rubbish right? It's horrible to watch and especially if you look at the movement of the people and objects, and the details.

Copying this thread over from Twitter (nope, still not calling it X!) where I responded to some concerns that an interaction time of 20ms+ was crazily high: INP measures (as much as possible) from the moment you interact (click a button, type a key...etc) until the pixels actually update. 🧵 1/12

🆕 The 202511 Chrome User Experience (CrUX) release is now live on BigQuery! Check out the announcement post for the full info: groups.google.com/a/chromium.o... Highlights below 👇 🧵 1/3

ICYMI we dropped the 2025 edition of CSS wrapped yesterday: chrome.dev/css-wrapped-... Lots of nice new CSS features. Cutting edge stuff, so many Chromium only for now, but at the rate of adoption of CSS features that surely won't be the case for long!

🎉 And we're live! 🎉 We just launched CSS Wrapped 2025: our annual recap of all things CSS & web UI that landed in Chrome over the course of the year. 🚀 This is a big one! We highlighted 22 new features to help you build better on the web. Check out: chrome.dev/css-wrapped-2025