Source maps are a vital part of modern web development, but the lack of a standard made it impossible for us to add new features or improve the debugging experience. This is the story of how we standardized source maps and how we continue to ship features through standards 📜 🧵

Vertical Tabs are available behind a flag in Chrome 145 (current beta) 1. Go to `chrome://flags/#vertical-tabs` 2. Set it to enabled 3. Relaunch Chrome 4. Right click the tabbar and choose “Move Tabs To The Side” Attached are before and after screenshots.

Been loving NVIDIA's NeMo models recently to complement Whisper for transcription, but the startup felt a bit heavy. So I went on a profiling adventure! github.com/NVIDIA-NeMo/... Turned out to be fruitful… stoked to land a big optimization in NeMO. github.com/NVIDIA-NeMo/...

I always prompt with "use modern CSS" but models rarely use *proper* modern, Baseline-y CSS. I want nesting, @layers, view transitions, oklch, light-dark(), etc. Does anyone have some prompt text which does a good job with this?

I dug into progressive image rendering and found a bunch of common assumptions aren't quite true. ➡️ JPEG & WebP progressive-renders worse in Safari ➡️ AVIF _does_ support progressive ➡️ But JPEG XL in Safari doesn't ➡️ JPEG XL decodes much slower than AVIF ⬇️ and more jakearchibald.com/2025/present...

forgot to put this up somewhere so here you go. visualize your favorite zlib stream! lynn.github.io/flateview/

I joined the HTML Day festivities today and made a lil homage to the <progress> tag: paul.irish/2025-progres... 💪 @htmlenergy.bsky.social

Why I 🧡 the web. drawafish.com Just draw the fish. Trust me. 🐟

My talk from I/O: a 10min jaunt jam-packed with DevTools Performance panel goodness. youtu.be/BHqxD9qr6Gw Really proud of what we've landed in the past year, including JS bundle analysis, framework tracing APIs, auto-annotations, CrUX context, and deep insights.

👀 Coming to Chrome DevTools in Chrome 138: CSS Value Tracing When you hover a --custom-prop in a `var()`, DevTools currently shows you the computed value. From Chrome 138 onwards, you can hover the `var` part to see how CSS actually got to that value.

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

Been annoyed by web fonts for a while. They’re big and they were connecting my blog to Google. I stumbled on modernfontstacks.com earlier today and now I’ve ditched my web fonts in favour of these. ~140kb shaved off the first load of my site. First impressions matter.

Is the WebDev Arena truly measuring webdev coding ability? This ML coding benchmark *requires* React/Tailwind and completely breaks with vanilla JS/other frameworks. The second-order implications of models competing on this narrow definition of frontend web development are rather troublesome.

Love how we're seeing more embrace of Markdown within non-developer apps, thanks to it being the lingua franca of LLMs. The Markdown-y copy/paste hooks of Google docs have been super handy.

Great news. We have a new position on the team for a Developer Advocate at the intersection of Web, Chrome, ChromeOS and Android. The position is in Waterloo - Canada www.google.com/about/career...

🔐 If you're a Google Password Manager user, I find the UI in Chrome at `about:password-manager` is a *lot* faster and less annoying than the passwords.google.com one. (Why is the web app so frustrating? Beats me.. I've filed bugs. I hope it improves, regardless.)

We've all seen visual regression tools that struggle with anti-aliasing, leading to repeated and noisy image diffs. Meanwhile, a layout shift at the top of a page/screenshot creates a disproportionately large diff (vs one at the bottom). Looking for quality, lightweight solutions in this realm :)

This is going to be brilliant to normalise different devices (especially you lucky folks working on high-spec dev laptops and desktop machines). Never knew whether to use 4x or 6x (or even the new 20x) slowdown? Now use the custom ones provided after a one-time calibration process. #webperf

New in Chrome DevTools: Skip irrelevant scripts in the Flame Chart! Debugging is faster and more actionable 🙏

Found a neat CSS trick to automatically swap between black or white text based on any arbitrary background color! With relative color syntax, you can use calc to adjust the text color depending if the background is above or below 50% lightness in the LCH color space.

They should put HTML in the browser

@brianholt.me got any eng contacts at present-day Reddit? I want to fix two bugs that are in a component of mine they use. :)

A while ago, @paul.irish and I tweaked the Chrome DevTools Performance Timeline to make it more easy for you to spot + debug non-composited animations. - Non-composited animations are marked with red triangles - Upon selecting, you now see the reason + relevant properties for why compositing failed

My last name being a TLD is finally paying dividends. (I just changed handle to the minimal @paul.irish) Thx ICANN! <3

Yup, I'm one of _those_ people. I'm sorry. :)