The first part of Declarative Partial Updates (`<template for>` out-of-order HTML) is now available, unflagged, in Chrome 150!! developer.chrome.com/release-note... The second part (the new JS setting APIs, include the streaming ones) we're still working on the spec side, but maybe for Chrome 152?

Chrome 150  |  Release notes  |  Chrome for Developers

CSS text-fit property, background-clip border-area, Focusgroup, and more.

developer.chrome.com

My talk on Modern Web Guidance is up! youtu.be/bo3i0FzDUYo This talk is a deep dive into how Modern Web Guidance works and why it's useful. 👉 Make sure you watch until the end, where I show some live demos that really highlight this tool's capabilities!

Unlock modern web capabilities in your AI coding workflows

YouTube video by Chrome for Developers

youtu.be

Level up your AI coding agents! 🤖 Modern Web Guidance brings expert-backed, evergreen skills to your workflow so you can build better web experiences faster. 💻✨

Sarah Drasner@sarahedo.bsky.social · 3mo ago

💥 Game changer for Web Development announced at GoogleIO- Modern Web Guidance! It’s expert-vetted skills for web development based on best practices of latest specs and APIs. It ensures your agent/coding harness doesn’t default to older and out of date patterns to build sites.

I say it every year - if you're even the least bit interested or involved in web performance, this is THE place to be every year. It's the one trip I prioritize my travel budget for. The talks are awesome, but the hallway track is unbeatable. The concentration of experts in one place is insane.

performance.now() conference@perfnow.nl · 3mo ago

performance.now() 2026 is coming. Ticket sales will open in May with cheap and ultra-cheap early bird tickets. These will be announced in our newsletter first. So subscribe via perfnow.nl/subscribe perfnow.nl

www.ncsc.gov.uk/passkeys

Chrome 144 introduces a new `<geolocation>`HTML Element to implement more impactful user location permission request flows. The new element serves multiple purposes, from location sensor access request as well as providing access to location data without the need to call the Geolocation JS API.

Thomas Steiner@tomayac.com · 7mo ago

Introducing the `<geolocation>` HTML element: developer.chrome.com/blog/geoloca.... This is the evolution of the `<permission>` element, and there's cross-browser interest! 📍🗺️

Signal API is now available on Chrome for Android. A user deletes their credential on the website, but the passkey remains in their passkey provider. The next time they try to sign in, the passkey provider offers a passkey that no longer works. A sign-in attempt will fail and this isn't ideal.

Signal API for passkeys available on Chrome for Android  |  Blog  |  Chrome for Developers

Learn how the Signal API for passkeys is now available on Chrome for Android, enabling better synchronization between relying parties and passkey providers.

developer.chrome.com

🎙️LET'S GET READY TO RUMBLE! It's been one of DevTool's most requested features… weighing at eiiighty-five votes… 10 years in the making… entering the ring from Chrome 144… Heeeerre's: Individual request throttling!!! developer.chrome.com/blog/throttl... 🥊 It's a knockout! The crowd does wild! 👏🙌🎉🥳

Throttle individual network requests  |  Blog  |  Chrome for Developers

Use the Request conditions tab to block specific URLs or apply custom network throttling profiles to individual resources.

developer.chrome.com

Great to see Banking Apps adopting Passkeys for a passwordless and more secure future! PS: Passkeys can be shared across web and app, making login seamless across channels (web to app or viceversa) by using the Digital Asset Link JSON!

Tim Cappalli@timcappalli.me · 9mo ago

Capital One 🤝 #passkeys

December is here (in a few hours in my timezone), which means the Web Performance "Advent" Calendar is back for its... 17th Edition! One article a day in the month of December. Be a part of it and contribute an article: calendar.perfplanet.com/contribute/

Contribute

Passionate about a topic? Working on a new tool? Have a technique you want to teach? Research you've done? Tell the web performance community! Send your articles to ssttoo@ymail.com. Please include: ...

calendar.perfplanet.com

Stop guessing and start debugging responsive styles automatically with Chrome DevTools MCP → goo.gle/3IPT2No Learn how a coding agent can find a visual bug on a specific device size, analyze the source code, update the CSS, and verify the fix with a live browser screenshot.

“Added preview support for Event Timing API (Interaction to Next Paint)” #webperf #CoreWebVitals

IntentToShip@intenttoship.dev · 10mo ago

Webkit: Release Notes for Safari Technology Preview 229

It's a bit of a surprise to me, but there are still tickets available for performance.now(), the most important web performance conference of the year: perfnow.nl I'm booking my travel, and hope to see you in Amsterdam next month!

performance.now(); 30th and 31st of October, Amsterdam

On 30th and 31st of October, 2025, the sixth edition of performance.now() will take place in Amsterdam—a single track conference, covering today’s most important web performance insights.

perfnow.nl

Announcing Chrome DevTools MCP! 🚀 Connect your AI coding agent to Chrome's powerful automation & debugging capabilities with ease. Learn more: developer.chrome.com/blog/chrome-...

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

Customisable Single Select · Issue #995 · web-platform-tests/interop

Description This covers updating the parsing for the select element to match the changes to the HTML spec, as well as styling changes from appearance: base-select which enables rich content and hig...

github.com

Una Kravets@una.im · 11mo ago

How useful is it for you to be able to style select elements? Is this something you've had to do before? Would you adopt the native browser API if it shipped cross-browser?

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...

Writing WebSocket client applications - Web APIs | MDN

In this guide we'll walk through the implementation of a WebSocket-based ping application. In this application, the client sends a

developer.mozilla.org

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.

Case Study: How Google created a connected experience for its new AI Mode using view transitions  |  Blog  |  Chrome for Developers

Bridging the gap between MPA and SPA: Making the transition into Google Search AI Mode feel seamless and connected with cross-document view transitions.

developer.chrome.com

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!

performance.now() conference@perfnow.nl · last yr.

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

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!

IntentToShip@intenttoship.dev · 12mo ago

Gecko: Intent to prototype and ship: improvements to <details> styling, including support for ::details-content pseudo element

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

performance.now(); 30th and 31st of October, Amsterdam

On 30th and 31st of October, 2025, the sixth edition of performance.now() will take place in Amsterdam—a single track conference, covering today’s most important web performance insights.

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...

Two lines of Cross-Document View Transitions code you can use on every website today

Arguably, the most profound thing about the web is the ability to link one page to another.

webkit.org

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 🧵

GitHub - GoogleChrome/web-vitals: Essential metrics for a healthy site.

Essential metrics for a healthy site. Contribute to GoogleChrome/web-vitals development by creating an account on GitHub.

github.com

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 🧵

Lighthouse is moving to performance insight audits  |  Blog  |  Chrome for Developers

Lighthouse is moving to performance insight audits

developer.chrome.com

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...

WordPress 6.8 Field Guide

This guide outlines major developer features and breaking changes in 6.8 and is published in the Release Candidate phase to help inform WordPress extending developers, Core developers, and others. …

make.wordpress.org

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.