Upvote this feature for Interop 2026: github.com/web-platform...

MDN just added a new section in the WebSocket API guide called "Working with the bfcache". Check this out if you are using WebSocket, you may be blocking BFCache and making user experience worse! developer.mozilla.org/en-US/docs/W...

If you thought we were done with View Transitions, guess again! A feature Chrome is working on, is “Scoped View Transitions”, which allow you to scope a VT to a subtree of the DOM. This unlocks things like concurrent transitions and prevents layering issues. developer.chrome.com/blog/scoped-...

This is happening today in ~3hrs. @weston.ruter.net joins me to discuss benchmarks as well as performance updates made on the #Wordpress Core platform. Join us! ✨ SPDY STREAM 009 ✨ 🗣️ Westin Ruter 📆 Wednesday September 10th, 2025 ⏰ 1pm EDT, 10am PDT 🔗 bit.ly/spdy-stream-...

🆕 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

Did you know Cross-Document View Transitions are being used in production on Google Search? developer.chrome.com/blog/google-... is a case study I co-authored with one of our engineers from the Google Search UI team.

performance.now() is coming to Amsterdam this October! This event is great both for the inspirational talks as well as for the opportunity to meet folks from different companies and backgrounds to discuss how to successfully tackle web performance challenges!

Very exciting news. With these changes, you can more easily build accordions such as seen in this recording. developer.chrome.com/blog/styling... Currently supported in Chrome and Safari, and soon Firefox!

performance.now(), the web performance conference, 30th and 31st of October, Amsterdam. Single track, the best speakers in the industry, plenty of your performance-mad peers around to have fascinating conversations. What's not to like? Let's introduce our speakers ... perfnow.nl

The Chrome DevTools Performance panel just leveled up! 🚀 Here's a 69-second taste of the new hotness.

BFCache can hugely influence your page performance for URLs high on Back Forward Navigation types. If you use CrUX or RUM and you see a lot of traffic in % attributed on Back Forward and few on BFCache maybe you are leaving money on the table! CruXVis can help you measuring this opportunity!

The one where I muse about how this simple bit of code radically changes how the web itself seems to behave… webkit.org/blog/16967/t...

We've just published v5.0.0 of the web-vitals JavaScript library for measuring Core Web Vitals. github.com/GoogleChrome... As a major release, this includes a number of breaking changes as detailed in the upgrading doc: github.com/GoogleChrome... Please read carefully before upgrading. 1/5 🧵

We're updating Lighthouse to be based on the same Insights we recently launched in the Performance panel of Chrome DevTools. developer.chrome.com/blog/moving-... This will help align the tools but will be a breaking change. So we'll make that change in Lighthouse 13 in 6 months. 1/3 🧵

WordPress 6.8 is out today. Including Speculation Rules in Core thanks ot some amazing work by @felixarntz.bsky.social !! make.wordpress.org/core/2025/03... It's a very conservative prefetch-on-mousedown default but site owners (or plugins) can customise that: make.wordpress.org/core/2025/03...

Alternatively, the CrUX History APIs are free and you can build your own dashboards as you see fit. There are also LOTS of great CrUX tools out there — many with a free offering to view history such as Treo, Calibre...etc. So that's another option.

🎥 The videos from our last meetup are now live on our YouTube channel! Here's the playlist: www.youtube.com/playlist?lis... Big thanks to @keerthanak17.bsky.social and @webx.bsky.social for speaking! ❤️ #webperf

In case you missed it cause you had better things to do on a Friday evening 🤷‍♂️, I wrote a detailed post on how to roll out speculation rules on more complex sites. Check it out.

Yay! new CrUX API goodness! LCP Type and Image Subparts are now available!, so I've added them to my free CWV History Tool here: tamethebots.com/tools/cwv-hi...

Awesome #CrUX update by the people from #Google (and also partially available in our free tool as well) 👏 This was added: → LCP image subparts → LCP resource types → Round Trip Time (RTT) tri-bins → RTT p75 and histograms We added #LCP resource type already as well (see attached). 1/4

We don't have an official CrUX Bluesky account, so for the moment I'll announce the monthly releases. And we're starting with a big one! 🆕 The 202501 release is now live on BigQuery! Check out the announcement post for the full info: groups.google.com/a/chromium.o... Highlights below 👇 🧵 1/10

Coolest thing ever🤩, our Baseline integration into RUMvision got featured as a use case web.dev/case-studies... Not something I could have predicted when we started our startup 3 years ago, and was looking through web.dev as a source of info, which makes this even cooler! 🥳

Great to hear about new business stories being published about how leading firms such as #RayBan from Luxottica takes advantage of #SpeculationRules #Prerender on Chrome to double their conversion rate while improving LCP and other CWV metrics! web.dev/case-studies...

With the start of 2025, the WordPress Core Performance Team is looking for 2 new Team Reps to represent the team as part of the broader project. If you want to nominate someone or volunteer yourself, don't hesitate and let us know in the post comments! 🙌 make.wordpress.org/performance/...

View Transitions Snippets: Getting all Animations linked to a View Transition 🔗 brm.us/view-transit... 🏷️ #ViewTransitions #JavaScript #Animations

3.6M Origins have BFCache not available in Chrome due to CCNS header usage (Source HTTP Archive via LH BFCache blocking reasons). I honestly doubt that most of these sites are using CCNS for valid reasons... web.dev/articles/bfc...

This is so well deserved. Not only is Pat one of the most brilliant people I've ever had the opportunity to work with, but he's so generous with his time—I wouldn't be able to do what I do without all the times over the years that Pat patiently answered my questions and helped me figure things out.

Did you know that jQuery outperforms React, what? 😳 Sounds like clickbait, but is reality. The HTTP Archive shows 82% of sites that use jQuery have good INP on mobile📱, while only 67% do when they use React⚛️. Not just sites, also libraries. Let's fix that👇#webperf kurtextrem.de/posts/improv...

#perfnow I have finally got my slides online! They are very media heavy so please be patient, but Keynote exported them all and I have uploaded them to www.jackf.io/talks/perf-n.... You'll find my slides and also all the links I mentioned during the talk.

Looks like Chromium is about to change how prefetches behave, so that only cacheable resources will be served from the prefetch cache: groups.google.com/a/chromium.o... If you're prefetching your HTMLs, make sure they are actually cacheable, even with a short lifetime.

US is famous for these kind of products but there are plenty in a Europe as well... youtu.be/cRykZDnJbW4?...

I forgot what it was like to have a feed focused on tech things I actually care about again 🙏

Would you want core web vitals In Safari? Can you help me understand how you would use them and why numbers in one browser isn’t enough? (These may sound like silly questions, but I’d love to understand *your* specific context and use cases)

Meet your #perfnow Help Desk experts Adam Read Alan Mooiman @slightlyoff.bsky.social @verlok.bsky.social Andrés Alvarez Sordo Andrew Betts Andrew Creskey @anniesullie.bsky.social Barneet Singh Brian Louis Ramirez @cliffcrocker.bsky.social @cdaveross.bsky.social (1/3)

Anyone interested in seeing how Compression dictionaries work for your dynamic content (live)? I'm experimenting with a Cloudflare worker that can proxy a site and apply a compression dictionary to the document responses. For example, CNN HTML payloads are 50-65% smaller: cnn.patrickmeenan.com

Planet Performance Calendar is a one-article-a-day Advent -style publication that runs in December since 2009, focused on Web Performance. If you (or anyone you know) want to share your experience, tool, research, rant with the #webperf community, please reach out calendar.perfplanet.com/contribute/

It's amazing to see how LCP and INP have improved over the past two years by country.

CrUXVis includes Navigation Types Breakdown that can help you understand how much traffic you could move from "back_forwad" to "back_forward_cache" on your site! Test out here: cruxvis.withgoogle.com Read more about Navigation Types here: developer.chrome.com/blog/crux-na...

Do you own apps and websites that share the same account system? You can signal to password managers that your users can sign in using the same credentials across your Android app and website, or across multiple sites you own. developer.chrome.com/blog/seamles...

UPDATE: GPT upgraded the threadYield implementation now using Scheduler.yield when available. Now GTP SRA Block Thread Yield is taking benefit of the .yield() method ensuring Script continuation. developers.google.com/publisher-ta...

I'm building a web perf starter pack but I'm still looking for folks to add - please let me know who I'm missing because I haven't found them all on bsky yet go.bsky.app/RVWSVqe