Fast and efficient brotli recompression using previous compression artifacts: dev.to/riknelix/fast-and-eff… *Amazing* work by @riknelix!! Up to 5.3% smaller files and 38% *faster* compression compared to Brotli 5!

If you ever struggled with understanding if your CSS performance issues are coming from style calculation or from layout, LoAF's styleDuration and layoutDuration is shipping in Chromium 158 to help with that groups.google.com/a/chromium…

Experimental soft navigation data now available in CrUX!! If your site is an SPA then see how your own Core Web Vitals data will change at: cruxvis.withgoogle.com/ And read this blog post for more details about how Core Web Vitals change in general: web.dev/blog/crux-experiment…

Wrote a bit about why I think WebMCP matters: blog.yoav.ws/posts/why_webmc…

socbb.org/bug-bounty-wins-th… @hjanuschka strikes again!!

We enabled streaming for @Shopify storefronts. The layout head reaches the browser before the template finishes rendering. Median-store TTFB down 29% at p75, 21% at p90. FCP and LCP down 2–6%. No theme changes needed*. performance.shopify.com/blog…

@yoavweiss @benjaminsehl hope we got this right

We made Shopify storefronts faster with automatic Early Hints. By finding and preloading render-blocking resources, we improved p75 FCP by 76ms and LCP by 100ms. No merchant or theme changes required. performance.shopify.com/blog…

@ChatGPT built-in browser speaks WebMCP and millions of @Shopify storefronts are live and ready! 🎉 That's a huge milestone and upgrade for your agent, which can now use site provided tools and efficiently explore merchant's catalog, build carts, and more. Pumped to support @OpenAI WebMCP challenge too: openai.com/webmcp-challenge — join in on the fun! 🤫 p.s. psst, need a winning idea? Head to UCP.new to explore how you can build new shopping experiences with Shopify Global Catalog, then install UCP-cli (github.com/Shopify/ucp-cli) agent skill and let it cook.

It has been a LONG time coming but @sergeyche @programmingart and @yoavweiss weren't falling for my ongoing procrastination. A test tool (and generator) for compression dictionary deployments: blog.patrickmeenan.com/2026/…

Hi! I'm working on a new HTML feature: filterable select There are two proposed API shapes so far: 1. Nesting <input> in <select> 2. Sibling <input> for listbox <select> w/id ref Option 1 is more ergonomic, but would break selects in older browsers Thoughts?

It has been a busy holiday weekend burning all the tokens (Fable, GPT 5.5 and Gemini all contributed)... Waterfall-tools can now render performance API data (including resource timing, LOAF and JS self-profiling): blog.patrickmeenan.com/2026/…

I'm proposing a way to be able to persist iframes across navigations github.com/WICG/proposals/is… Best idea or worst idea??

Recently, we fixed an unprecedented number of latent security bugs in Firefox identified by Claude Mythos Preview. Here's how we approached this work, what we found, and what we learned: hacks.mozilla.org/2026/05/be…

It's been a while since I've seen a clear data-based study on the relationship between performance metrics and conversion. @krzksz gives us just that: shopify.com/enterprise/blog/…

Standards are words and talk is cheap. A standard's success is measured by adoption, which is earned by solving right problems, with the right primitives, and running code. Universal Commerce Protocol has been a rocket ship. We chiseled it out of decades of shared experience running the world's largest commerce and consumer platforms, and it struck a chord, pulling contributors and adoption from across the agentic ecosystem. Case in point, the 04-08 release packed a punch. We landed support for: catalog for product discovery, cart building, post-order operations, context & intent for personalization, trust signals, and eligibility claims. Today the 🚀 trajectory accelerates. We're welcoming @amazon, @Meta, @Microsoft, @salesforce, and @stripe to the UCP Tech Council 🎉, working alongside @Google, @Shopify, @Etsy, @Target, and @Wayfair. Combined, these platforms touch billions of users, millions of merchants, and trillions of dollars in annual transactions — all rallying behind UCP as the one open protocol for the agentic era. Tech Council update: newsfilecorp.com/release/294…

sizes="auto" landed in Firefox 150, making responsive images simpler and more reliable. Here's when you can use it, and how…

Really excited to see the support for compression dictionaries that @Cloudflare is working on. Great background on the feature in the blog post as well (as you'd come to expect from their awesome blog).

I bring you "Waterfall Tools": blog.patrickmeenan.com/2026/… I've been wanting to build a fully-JS client-based waterfall viewer for a really long time and, with the help of Gemini and Opus finally put one together. It's scary how capable it is for < 100 kB.