So far I've received 11 submissions for this year's #HTMHellAdventCalendar. They look fantastic, but, you know, I need at least 24. You can write about anything you want related to HTML. There's no “too basic”; we need more fundamental HTML knowledge out there because we suck at the basics. 1/2

Announcing our public preview of Chrome DevTools MCP! Experience the full power of DevTools in your AI coding agent→ goo.gle/4pDE6Tk With Chrome DevTools MCP, your AI agent can run performance traces, inspect the DOM, & perform real-time debugging of your web pages.

Finally, a good use of AI! Snark!!

Before, you needed a plugin to use Baseline semantics in your Browserslist queries. Now you don't! Just give it a target like `baseline widely available` and it'll work out of the box Available in [email protected] and later web.dev/blog/browser...

✨ SPDY STREAM 011 ✨ w/ @krzksz.bsky.social & @yoav.ws After deploying the SPECULATION RULES API to their merchants, they join me this week to discuss the experience and their findings. Join us! (updated day and time) 📆 Thursday Sept 25 ⏰ 11am EST, 5pm CEST 🔗 bit.ly/spdy-stream-011

Oh it seems Manning have upgraded my "HTTP/2 in Action" book to include the liveAudio for those that prefer listening to reading! www.manning.com/books/http2-... Use code lahttp40 for 40% discount on that. Or code 39pollard for 39% discount on the other formats.

We're launching a GoFundMe to cover legal fees to #FreeJavaScript trademark from Oracle. We need to raise $200k to make full use of the discovery phase in the trademark cancelation petition. This is a critical step in protecting the JavaScript name for the whole community. 👉 javascript.tm

Oct 14 Firefox 144 will ship JS-powered view transitions with `startViewTransition`. 🎉 Of course, this is only the first step because we're all waiting for cross-document view transitions, too, but I'm still very happy about view transitions being on their way to work everywhere.

The URL Pattern API is now available across all major browser engines! It's now much easier to work with URLs. See developer.mozilla.org/en-US/docs/W... for more info.

It's common for folks who should know better — including people who work on browsers — to claim some vendors "don't follow standards" when attacking certain designs. This isn't just wrong, it hurts our ability to think clearly about how make a better web: infrequently.org/2025/09/stan...

Great to see Speculation Rules getting some love at Shopify! performance.shopify.com/blogs/blog/s...

The Call For Papers for this years HTMHell Advent Calendar is still open! Please submit your ideas. You can write about anything related to HTML. docs.google.com/forms/d/e/1F...

Got questions about building Chrome Extensions? We’re recording some new videos for the @developer.chrome.com channel in October, and I’d love suggestions for topics we should cover: www.reddit.com/r/chrome_ext...

Great post from @erwinhofman.bsky.social on webperf Interop proposals: www.rumvision.com/blog/interop... Upvote your favourite ones to let us know which are important to you!

Well, the time has come, my contract with Estee Lauder is ending… :-( You can read the details in my post below, but for now, if you happen to know of a clunky website that could use some web performance love, give me a shout! ;-) aarontgrogg.com/blog/2025/09...

This is what I use alt text for! Stop thinking accessibility is only for those with an obvious, visible disability. It helps us all.

You don't necessarily need to say "image of" in your alt text for users to know it's an image. Screen readers will announce that it's an image. But it can help readers to specify if it's a hand-drawn image, Polaroid, infographic, screenshot, chart, map, diagram, or so on.

LCP and INP are part of Interop 2025 so hopefully coming to Firefox and Safari this year! 🥳 Checking in, I'm seeing: Firefox - LCP is in stable 🎉 - INP is behind a flag 🔜? Safari - LCP is being actively worked judging by spec questions 🏗️ - INP is available behind a flag in STP 🔜? #CoreWebVitals

Are there any patterns from JS UI libraries and frameworks like React and Svelte that you wish were just part of the darn web platform?

Need help with web performance optimization? Have a tricky new build you're working on? I have two projects wrapping up and am available for new ones starting next week. sia.codes/services/

Thrilled to share my new role as the tech lead across frameworks at Google! My initial focus is boosting productivity with AI. While this means I'll be less hands-on with Angular with fewer public appearances, I'll be supporting the team and the rest of Google more than ever 🚀

performance.now() is coming! As tooling improves, is performance testing becoming any easier? @csswizardry.com, who spends every day auditing client projects,, thinks confusion has increased. Let's ensure that every test we run has a purpose and gives us useful data. perfnow.nl/speakers.htm...

I've hit level 17 and it's fiendish. I will accept being a robot now.

On the Chrome team, we've a cool new origin trial for you to try in your apps: the Proofreader API: developer.chrome.com/docs/ai/proo.... ❌ tyop → ✅ typo ```js await (await Proofreader.create({ expectedInputLanguages: ['en'], })).proofread( 'Let us knwo how it foes', ); ``` #BuiltInAI #WebAI

Curious about what we do on the WebDX community group (i.e Baseline and web-features)? We're organizing a Reddit AMA on Thursday. Ask your questions here: www.reddit.com/r/webdev/com...

pnpm v10.16.0 adds "minimumReleaseAge", a setting for defining how long a version has to have been published before pnpm will install it. A nice countermeasure against accidental installs of short-lived compromised packages before they get taken down. Not a 100% fix, but a great additional step!

⌨️ Blog post: For anyone who has to deal with very long GitHub issues, a way to load ALL of the comments using a bookmarklet, updated for their new and much more cluttered markup. meyerweb.com/eric/thought...

👀 Browserslist 4.26 - Now supports Baseline Queries Thanks @en.sitnik.ru @tonypconway.com , this will be way more convenient in many cases!

Even if you don't contribute a proposal, you can participate in Interop 2026 by upvoting your most desired features, here are a few of mine: Invoker Commands: github.com/web-platform... Scroll-driven Animations: github.com/web-platform... LoAF: github.com/web-platform... #webdev #webperf

Edge has the same built-in AI APIs that Chrome does (Prompt, Writer, Rewriter, and Summarizer, soon Translator). If you've played with it in Chrome, give it a try in Edge and let us know your feedback. See: learn.microsoft.com/microsoft-ed... learn.microsoft.com/microsoft-ed...

performance.now() is coming! Nothing's set in stone, but @tunetheweb.com may speculate about the Speculation Rules API that speculates about future navigations. We speculate that he may even speculate about what you can expect in the near future. perfnow.nl/speakers.htm...

Bye Bye CrUX Dashboard, I'll always be nostalgic for your stacked bars of Goodness: developer.chrome.com/blog/crux-da... You can use tamethebots.com/tools/cwv-hi..., the cruxvis.withgoogle.com or one of the many other great free tools that use the CrUX History API.

Wow, do I wish I had been able to attend this presentation. At least I got to enjoy the slides, and you may, too. Thanks for sharing, @matthiasott.com.

🆕 The 202508 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

I say this every year and always mean it: WOW, what a speaker (and MC!) lineup we have for @perfnow.nl conference this year! I can't wait to see all these folks on the stage! This is when #PerfNow ticket sales start to go bananas — and we always sell out — so lock in your ticket soon! perfnow.nl

Seeing some nice proposals being made for #Interop2026: github.com/web-platform... If you want to suggest one (or more), now’s the time to do so.

Thank you to @observeruk.bsky.social for this thoughtful review. “Berners-Lee is clear-eyed about the benefits and the dangers. This Is for Everyone contains some very sharp thinking about what we need to do now.” We must fight for the web we want. observer.co.uk/culture/book...

Interesting read… observer.co.uk/culture/book...

Good job! We’re almost ready to switch these over to be the default and turn off the old audits as explained here: developer.chrome.com/blog/moving-... Have you switched over to the new Insights yet?

Hey folks, I'm looking to schedule the next PerformanceObserver meetup and need some new CFP submissions. I have a few experienced #webperf speakers on there, but I like to break it up with either newer speakers or new-to-webperf speakers. performanceobserver.dev/call-for-pap...

Interop 2026 has started asking for proposals. web.dev/blog/interop... What would you like to see being made more interoperable across all the major browsers?

“I called the number, and to my absolute surprise there were currently more callers than usual.” Tee hee!

What if some client-side browsing features were part of the web platform? Direct CSS reflection of URL state, snappy pending/optimistic UI, URL-to-scroll-snap binding, and some basic same-document navigation use cases, with JS being only an option. github.com/WICG/declara... Inviting feedback!

🩺 You don’t *have* to use Obs.js to adapt your site. You can use it as an analytics add-on and send data off to @speedcurve.com! csswizardry.com/Obs.js/demo/...

Really excited to be speaking @perfnow.nl this year—my favourite conference run by some of my favourite people! If you're into web performance (or wanna be!) and like a great conference with a super friendly vibe then pop along to Amsterdam at the end of October. Tickets selling fast! perfnow.nl

We have AI now www.youtube.com/watch?v=8-lg...

Not being able to right-click links is often a sign that search engines won't be able to use those links either (if there's no href URL, it usually can't be crawled). It's a simple way to check if a JS-based site is crawlable (not perfect, but fast & easy). #SEO

Web sites that open in a new tab with target=_blank don't particularly annoy me. I think it's OK for a site to be opinionated here. What DOES annoys me is if don't realise they are going to use a new tab and I try with right click and get a new tab of "about:blank" cause of course links need JS 😡

🤔 Why do browsers throttle JavaScript timers?

Most devs don’t understand caching. And it shows. Slower sites. Fragile infra. Bigger bills. All because a few headers are misused or ignored. I wrote the complete guide to HTTP caching - every directive, pitfall & trick, from Cache-Control to Cloudflare quirks to the AI-mediated web.