I've proposed a series of changes to popover=hint. If you use web popovers, I'd love to know if the changes in the first post of this issue make sense, or, more importantly, if these changes would break your current usage of popovers. github.com/whatwg/html/...

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.

Okay, clearly y'all love colour games, so with millions of plays on jnd & jnd-hard thought I'd dust off and polish up the _original concept_. Hue shift: www.keithcirkel.co.uk/hue-shift/?r... Drag one colour to match the other, 10 seconds to do it. You know the drill. Make me proud gang.

@bram.us Anchors aweigh! Tethering Elements in Pure CSS with Anchor Positioning. Talk from #SotB26 is now live. 2026.stateofthebrowser.com/speaker/bram...

Want to know even more? I'm speaking at #cssday where I will give a talk called "CSS Doom Lasers". Where I will talk about CSS and DOOM and much more. Hint: Lasers. Tickets are still on sale: cssday.nl

CSS is DOOMed! I've build DOOM in CSS and every wall, floor, barrel, and imp is a div, positioned in 3D space using CSS transforms. cssdoom.wtf Try it out! But... not every browser can handle it. This is taking the browser to its limit. Chrome has some issues. Safari too. Bugs will be filed.

github.blog/news-insight... You know the drill: yet another service really wants to train on your data. Opt out by visiting github.com/settings/cop... and changing the option to "Disabled".

The recording of @kitation.co.uk talk ‘The Plateau of Accessibility Compliance: Where do we go from here?’ is now available to watch online! 2026.stateofthebrowser.com/speaker/chad...

The recording of @jason-williams.co.uk talk ‘Temporal: It’s about time!’ is now available to watch online! 2026.stateofthebrowser.com/speaker/jaso... And Temporal has reached Stage 4: www.igalia.com/2026/03/13/T...

Spec proposal merged. HTML video and audio lazy loading is now a web standard. github.com/whatwg/html/... html.spec.whatwg.org#the-video-el... html.spec.whatwg.org#the-audio-el...

Always use indexes.

I'm speaking at Web Day Out on Thursday in Brighton. The line-up looks great, and tickets are still available webdayout.com You can get a 10% discount via ti.to/clearleft/we... My first talk in a couple of years 😬. It's currently running at 40 minutes but the slot is 30, so I have work to do…

For those who want to test their perception of colour, I made a little game called "What's My JND" www.keithcirkel.co.uk/whats-my-jnd...

I spent too much time looking at too many colo(u)rs to try and optimise them for csskit. Here are some interesting findings. www.keithcirkel.co.uk/too-much-col...

Open UI has been working on speccing out the focusgroup attribute: a declarative way to support roving focus & add keyboard nav to composite widgets like toolbars/menus We'd love your feedback! Learn more & see open questions: developer.chrome.com/blog/focusgr... H/t to Edge folks for prototyping

Took a day off of work to figure out what is the perceptual boundary for rounding css color values. I spent the morning writing a whole bunch of complex code binary searching by computing delta-e - the answer is 3. 3dp. All this code is over-precise: github.com/search?q=lan...

Morning. It’s State of the Browser Day #SotB26

Firefox 148 is out now, and adds some great web platform features: 🎉 The HTML Sanitizer API 🎉 CSS shape() 🎉 Trusted Types 🎉 Nav API's addHandler 🎉 Iterator zip & zipKeyed 🎉 ancestorOrigins And more! developer.mozilla.org/en-US/docs/M...

If you’re a framework author or maintainer make your voice heard and help improve web standards! The W3 Web Frameworks Community Group (WFCG) is official! Come and share your opinions, open to all! www.w3.org/community/wf...

*web frameworks klaxon* If you work on a web framework then there is a w3c proposed community group: the Web Frameworks Community Group, a place for framework folk to feedback to browser vendors about what they want to see! If you want this it needs your support! www.w3.org/community/gr...

This is to collect research for HTML input pickers such as date, time, datetime and colour. "Please send us examples of good (or bad) ones. Even if they have extra functionality that doesn't exist yet (e.g. date ranges, perhaps we can add that in)." github.com/openui/open-...

And she'd be right

Happy Monday CSS gang. Let's improve CSS minifiers! Here's a suite of 350 minifier tests I've written that show there's lots of opportunities for minifiers to do better: www.keithcirkel.co.uk/css-minify-t... I know you all can help add 350 more, so come contribute! github.com/keithamus/cs...

Happy Monday CSS gang. Let's improve CSS minifiers! Here's a suite of 350 minifier tests I've written that show there's lots of opportunities for minifiers to do better: www.keithcirkel.co.uk/css-minify-t... I know you all can help add 350 more, so come contribute! github.com/keithamus/cs...

github.blog/changelog/20... This is a really wonderful addition. Long requested for but in the wake of AI, a necessity.

Browser developers are working on custom form controls ( `appearance:base`), the next giant task is looming: customisable input type=date/datetime/color pickers. These are huge and have wildly varied UI. Send me your examples, I'd love to see them and build up a body of these pickers.

If you had to pick _one_, which web platform feature would you like in Firefox that isn't part of the Interop 2026 effort? hacks.mozilla.org/2026/02/laun...

It's time for Interop 2026! This is a cross-browser effort where we agree on a set of focus areas to improve compatibility. Here's how things went in 2025, and what we're taking on for 2026: hacks.mozilla.org/2026/02/laun...

Do you have ideas about what kind of default lint rules a css linter should check by default? I'd love to hear ideas in github.com/csskit/csski....

Happy weekend! lolaslab.co has got a fresh new look. 😎 I’m going to be slowly working on updating the content but I’m happy with how it looks now.

Really enjoyed the opportunity to present this HTML standard proposal at the WhatWG meeting today github.com/whatwg/html/...

Some Monday watching to get your brain juices flowing for the week: www.keithcirkel.co.uk/bad-at-css/ I spoke & wrote about how bad I am at CSS, and showed some truly awful things you can do with the language. Huge thanks to @nn1.dev for giving me the opportunity! www.youtube.com/watch?v=cJno...

Now I know enough about AI to grok what MCP is, it irritates me because fundamentally: Make a cli tool instead! Then a human can use it too. It’s not stateless? That’s what unix sockets are for! Once again we’re reinventing stuff from the 70s and making it worse.

Take me down to the Parallax city where the far moves slow and the near moves quickly

London is officially the best city in the world for food. That's going to rile the sceptics who have one joke. www.cntraveller.com/article/lond...

CSS anchor positioning is newly baseline! This opens the door for lots of new creative CSS. It's a huge feature, but here are the basics.

Firefox 147 just landed & it's pretty huge in terms of web features: 🎉 CSS anchor positioning 🎉 The navigation API 🎉 View transition types 🎉 Brotli support in Compression/DecompressionStream 🎉 CSS module imports And more! https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/147

The speaker line up for #SotB26 is announced. @bram.us @cassiecodes.bsky.social @kitation.co.uk Fiona Safari @jason-williams.co.uk @mikehall314.bsky.social @zachleat.com It will be a full day of very interesting sessions and we can’t wait to see you all there! 2026.stateofthebrowser.com/speakers/

I've seen a number of people request a way to imperatively link a form control and a label via a property such as .forElement on the label. Can you send me your concrete use cases if you're one of these people?

Been deep in some browser & standards contributions lately and feeling renewed love for this idea that when companies need a certain feature, they can build it one-off, or they can propose (and prototype) a way to build it into browsers for everybody. Latter’s more approachable than many think!

Gecko: Intent to Prototype: "Customizable Select"

Tickets for #SotB26 are on sale - Get yours now! When? Saturday 28 February 2026, 09:30 - 17:00 GMT. Where? The Barbican Centre, London. Ticket types: In-person, Online, Diversity In-person and Online. *Diversity ticket applications end Thursday 26 February 2026. 2026.stateofthebrowser.com/tickets/

We have a diversity scheme for State of the Browser. This is for Students, people new to our industry, people from under-represented groups, unemployed, or anyone who feels they fit (we don't ask for proof we just trust people) 2026.stateofthebrowser.com/tickets/#div... Please share

A rough prototype, but it's working! `[email protected]` now has a linter language! you can define "rule sheets" with a css-like syntax, then run them against your actual stylesheets and it'll lint your css in a split second! Run `csskit tree` to see how to select nodes. `npm i csskit@latest` ;)

Who’s interested in some css gradient easing functions?

❓ Do you have a need for range inputs with 3+ sliders on the web? Folks are scoping out this work, and want to know your use-cases ⬇️ https://github.com/openui/open-ui/issues/1337

Oh hello! We've had a bit of a rename & rebrand (formally FirefoxDevTools), but the content will be roughly the same as it's been for the past few months. We're looking forward to posting more on web platform & DevTools features.

We have Custom Elements, but do we also need Custom Attributes? This was discussed at TPAC. Is it something you'd like on the platform? https://github.com/WICG/webcomponents/issues/1029

We know that before we announce our next speaker, you like to get to know them a bit. Our clue for you today is…Their dog is an internet superstar and has appeared on many industry videos. On Friday, we will officially announce them, so you have until then to try to figure out who this is.🤫 #SotB26