Excited to dig into this.

Chrome shipped an LLM Prompt API to the web platform. At Mozilla, we oppose this API. Here's why:

✍️ New Article: Better fluid sizing with round() I wrote about how CSS round() enhances the values you get from clamp() in sizing, typography, and spacing. Why it matters, and how to use it. 🔗 ishadeed.com/article/css-round

Decided to replay uncharted lost legacy as it has been awhile

It May already, and I only just started planning my first web article (on view transitions) of 2026.

BREAKING: Reform UK leader Nigel Farage bought £1.4m house in cash shortly after receiving £5m personal gift from crypto-billionaire Christopher Harborne. Reform says the "offer and process" of buying the property commenced before gift. Intriguing story by @alifortescuenews.bsky.social

To the surprise of absolutely no one but Wes Streeting.

I’ve been working with a client who runs a lot of social media and ad campaigns, so we’ve been deploying the experimental `No-Vary-Search HTTP` header. It’s amazing to see it actually working! Read all about it here: csswizardry.com/2026/05/bett...

Adiós Leeds 👋 been great to be back for a few days.

"Every time we fire [the #AI -powered 'slopgun'], we decrease the tickets but increase the workload" - actual satire at a web dev conference. And interactive. Amazing from @cassiecodes.bsky.social at #AllDayHey

Had amazing time at @heypresents.com, so sad it was the last one. 😭

Wouldn't be Leeds trip without having a pint at Northern Market

Finally in Leeds for @heypresents.com tomorrow.

Gecko: Intent to Prototype: Speculation Rules - Same-Origin Prefetch

A really important thread here. An industry without people like Josh producing extremely high quality education really is bleak.

don't let tech companies make their marketing and revenue aspirations part of the web platform challenge

One of the most important pieces about web performance that I've ever worked on is finally live. After a few months of work, my analysis of the correlation between site speed and conversion across the entire @Shopify platform is out: www.shopify.com/enterprise/b...

This may have actually changed my mind about everything, I didn't expect that. Do take a read and keep your mind open.

“If th[e] tools aren’t under the control of experts who care deeply about the end result, what you end up with is slop.”

Wanna measure Core Web Vitals for SPAs? It's been a long-standing gap, but one that we've been working hard to fill. We're approaching the final stages and have launched one last origin trial (🤞) as the "last call" before we ship it! More details: developer.chrome.com/blog/final-s...

Really looking forward to this.

It's really sad to see the @developer.chrome.com account pumping out AI-style replies that don't really make sense. These accounts used to be run by DevRel. Now they're run by marketing. bsky.app/profile/deve... bsky.app/profile/deve... bsky.app/profile/deve...

Started reading a new book on web performance and ai by @addyosmani.bsky.social

Rather than the same old boring internet pranks, I thought I'd build something more fun this April Fools. CSS or BS. Can you tell your CSS properties names from BS? www.keithcirkel.co.uk/css-or-bs

reading: What Is CSS Containment and How Can I Use It? csswizardry.com/2026/04/what... — my prayers were answered! Harry explains all 🙏 for my next wish...

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?

📝 New CSS Article! If you have seen my graph theory demo and wondered how it works, then the article is finally live! frontendmasters.com/blog/two-cir... I was playing with two circles and anchor positioning, and ended up creating a shortest path algorithm. Modern CSS is fun!

Cool view transition demo by @paolo.ricciuti.me !

Point blank is now a part of the Browser.

Honestly feels reality is being written by a game of card against humanity at this point.

After implementing Compression Dictionaries back in December, I sat down with @yoav.ws and @patmeenan.com to discuss getting the most out of them and provide some visuals for those new to the concept. Check out the video below: youtu.be/YR2er3EiYnM / lessonsofacto.com/videos/032-c...

Seeing that BoJack horseman ended 6 years ago:

Decided to build a calendar grid with web components and view transitions to add animation for back and forward with view transition types. iankduffy.com/examples/vie...

Resource heavy data centres running models that generated CSAM, assisted suicides and are all trained on stolen material. The boat is already far too long gone for this type of groupthink bullshit. Mozilla could have fully revived themselves in being opposition to AI, but another foot gun it is.

How does speed impact how visitors experience your website? And how can metrics hide real-world problems visitors face? My new article explains the impact of performance on user experience and behavior + how to interpret metrics in context. www.debugbear.com/blog/web-per...

Kemi discovering after 15 months that Robert Jenrick has been plotting in "secret"

This week's Web Weekly is about to hit all the inboxes in just a little bit! As always, it's jam-packed. 🎉 webweekly.email/archive/web-... If you're into web dev news close to the platform, you should check it out!

Trump "military operation" list youtu.be/V1508wboZXk

New year, new unit test failure due to someone forgetting to mock time.

Tips for Making the Performance Panel Less Overwhelming, by @duffeh.bsky.social (@perfplanet.bsky.social): https://calendar.perfplanet.com/2025/tips-for-making-the-performance-panel-less-overwhelming/ #performance #devtools #browsers #chrome #google

Web Performance Calendar day 31 article 4/5: @twnsnd.com on Compression Dictionaries to dramatically shrink responses (60–90% smaller than Brotli/GZIP). Why adoption is slow. Practical architectural decisions and implementation tips to get huge bandwidth wins. calendar.perfplanet.com/2025/from-th...

My article for Performance Calendar is live, looking at tips to help focus when doing performance traces.

Web Performance Calendar day 27 with @nucliweb.net on using Chrome DevTools for fun and profit: inspect heavy files in Network panel, monitor Core Web Vitals, record performance traces, validate optimizations, and more. calendar.perfplanet.com/2025/chrome-...

Web Performance Calendar day 26 with Sébastien Mischler on HTML streaming/flushing and how this old trick (featured in the first edition of the calendar) applies to today's CSR world. Show content now, not after JS finishes thinking. Fast pages, happy users. calendar.perfplanet.com/2025/revisit...

Can't wait for the loosened up, non-perfect, but quickly shipped AI-enhanced updates to hit my banking and insurance services next year. Im sure there will be no issues there at all.

Web Performance Calendar day 21 with Conor McCarthy and lessons learned from web perf client site reviews calendar.perfplanet.com/2025/insight...