Annie Sullivan

Clicking a link in a single-page app doesn't trigger a full page load. That's why it's tricky to measure. Chrome DevTools now analyzes these soft navigations in Performance Insights, alongside Live Metrics and trace views → goo.gle/4i2xbRL

Over time, we've evolved CVW to best fit how the web is written, and we've found that giving SPAs their own unique metrics has had the best outcome. Credit to @anniesullie.com and @alextcone.bsky.social More here, including access, and plans for SEO: web.dev/blog/crux-ex...

🧪 We've expanded Core Web Vitals to include support for soft navigation (SPA)! Since SPAs are handled differently in implementation, they have required bespoke custom measurement, making it hard to compare directly across sites. Measuring performance is a little art, a little science. 1/2

Things I hope to push forward at TPAC: - Declarative fragment / client side include - declarative skeleton/shell - CSS navigation matching - parser/patch reflection in mutation observers - responsive image improvements - connection allowlists - focusreset - CSS module imports Gonna be interesting!

This is a great post from @gustav.ernberg.se and shows how you can use the BigQuery CrUX data to do analysis across sites to see the impact of the soft nav change announced this week. SQL included too to make it easier for you to do similar! gernberg.com/posts/2026/h...

@benschwarz.bsky.social made this awesome graphic to show the impact of soft navigations on LCP. I should have credited him (and would have if I realized)

The pitch for single page apps was always “it’s faster after the first load”. Google’s Core Web Vitals, used in search ranking, now measure soft navigations. It’s true: LCP drops by about a third. But, I don't think SPAs are ever really worth all the compromises and extra code.

I’m pleased to see soft navigations count towards LCP. This was an argument I made when I worked on Google Chrome because single page apps can provide much faster UX. Let’s say goodbye to the outdated nonsense metaphors that JS is smog or a traffic jam. It never made sense — now we have the data.

CrUX now has experimental data for soft navigations for LCP, INP & CLS, helping close the gap on those pesky SPAs! I have added to my CWV tool here: tamethebots.com/tools/cwv-hi... Read more about the release here: web.dev/blog/crux-ex...

We have also published a detailed blog post from @anniesullie.com with details about how these data change the Core Web Vitals metrics for sites that experience a lot of soft navigations. And when we expect to migrate them out of the experimental stage. web.dev/blog/crux-ex... 4/10

🆕 The 202609 Chrome User Experience (CrUX) release is now live on BigQuery, and we also have an exciting addition to CrUX this month! Check out the announcement post for the full info: groups.google.com/a/chromium.o... Highlights below 👇 🧵 1/10

I'm super excited to announce that today we've added experimental versions of Core Web Vitals metrics including soft navigations to the Chrome User Experience Report! You can see them in BigQuery, the APIs, and CrUX Vis. Check it out! web.dev/blog/crux-ex...

A new W3C Community Group is being created to promote minimising dependencies and simplifying development.

What have you always wanted to know about CrUX? Tee me up with questions in your replies or, better yet, tune in to ask your question live!

This is me! We're focusing on a few areas next month and I'm leading the "Paper cuts" area. So spam me with your bugs, please - and please file them yourselves first so I can triage them internally 😁

We just sent out a TEST MAIL to our mailing list. Last year quite a few people didn't see the announcement mail and missed the early bird ticket sale. So this year we run a test first. If you're subscribed to our mailing list, please make sure you got the test mail. Or perfnow.nl/subscribe

✨ SPDY MEETUP 005 ✨ 📍 New Performance API, Data On CWV Navigations We're back in the @mozilla.org Toronto office w/ great presentations 🗣️ @anniesullie.com 🗣️ @mmocny.com 🗣️ @basschouten.bsky.social 🗣️ Lightning talk? 📆 Wednesday May 13th 🎟️ RSVP below if in Toronto www.meetup.com/spdy-meetup-...

Look, the Web Engines Hackfest is now a W3C-endorsed conference: www.w3.org/events/confe... Some working groups might arrange meetings at the hackfest. Thanks to W3C for your support and collaboration.

ICE out in Ypsilanti today Stay safe and keep your folks safe Please

I'm a part of ParaCliffHangers. It is a group that makes rock climbing accessible to disabled athletes (and future athletes!) We're hosting Owl Night at Pacific Pipe on Saturday 3/14. The gym will be open until 3am. Get tickets paracliffhangers.rallybound.org

Gretchen Whitmer is on point: We need more homes and allowing more choices and more building will help get us there. @abundanthousingmi.bsky.social #a2council #shareourcity #neighborsformoreneighbors #annarbor #a2 #michigan

FBI, HSI, and ICE detaining someone at the corner of Forest and Prospect in Ypsilanti. 5 unmarked cars. ~ 10 officers.

A shocking 8.5% of sites that use CDNs deliver some static content directly to end users via cloud storage! Many are not compressing or caching this content either. This comes at a significant performance cost. Details, examples and @httparchive.org stats here - paulcalvano.com/2026-02-09-s...

www.mlive.com/news/ann-arb...

Vigil in Ann Arbor for Alex Pretti.

here's a brief look ahead at what we have planned in the e18e community for 2026 🎉 great collaborations, and many useful developer tools are in the works. also a huge thanks to all who contributed so far - many of the libraries, tools, and frameworks we use today are faster because of you 💙

I just merged the code change for this. We'll now have new Device Memory API limits from Chrome 146 and other Chromium-based browsers: - Android: 2, 4, 8 - Others: 2, 4, 8, 16, 32 Replacing the old values of 0.25, 0.5, 1, 2, 4, 8 which have grown outdated. Next up, updating MDN documentation...

Big news! Google have sponsored the @e18e.dev community $10k via their Chrome performance fund 🎉 I'm very thankful we've managed to create a space and a community people appreciate. Sponsorships like this will benefit the ecosystem, not just this community

I am running for #A2Council in the Fourth Ward! Please support our people-powered campaign and help us lead Ann Arbor forward. secure.actblue.com/donate/sova2...

Answering some of your questions about what it means now LCP and INP are "Baseline Newly available" across all major browsers. Let me know if you have any more! web.dev/blog/lcp-and... #CoreWebVitals #webperf

Calling all web developers! Browsers are all meeting up next week (www.w3.org/events/tpac/...). I want your voice to be heard! Tell me your biggest problems, and tell me what you want to see from the platform. What problems are tough to solve, but could be easier?

There is an election today in the Washtenaw Intermediate School District. I think you should vote Yes on the Career Technical Education Millage: www.damnarbor.com/2025/11/elec... #a2Council #YpsiCouncil

We have a special visitor at the Downtown Library today! Thanks, @davidzinn.bsky.social!

It’s gonna be a fun day at the Downtown Library! Join us for Dead Media Day from 11-3 Sunday and enjoy the vintage arcade. No tokens required!

Really excited to be speaking @perfnow.nl this year—my favourite conference run by some of my favourite people! If you're into web performance (or wanna be!) and like a great conference with a super friendly vibe then pop along to Amsterdam at the end of October. Tickets selling fast! perfnow.nl

Exclusive: a Michigan Campaign Finance Act complaint has been filed against Ann Arbor's Library Green Conservancy. The complaint alleges LGC's advocacy against Props A & B violates state law limiting how 501(c)(3)s can engage in politics. Read more here: www.damnarbor.com/2025/07/excl... #a2Council

Did my second Spartan Race last weekend, my first in the age group category. Won the bronze! Had a ton of fun; love training for these with my kids.

DevTools 🤝 MCP - Or as @tej.as named it when I was pitching this over at @jsnation.gitnation.org in our chats....'Self healing mode'. Quick tease of something I've been hacking over the weekend as I prepare for I/O connect and just before. www.youtube.com/watch?v=hP_e...

Once again, Congresswoman Tlaib is a real one. And um. @debbiedingell.house.gov ? Could you just not (support manufactured war on Iran ffs)? And say that publicly? Seems like not too much to ask. Thanks in advance, I hope, but get on this.

Especially if you're on the fence about it, protest today. Fascism is isolating and lonely. Its very goal is to make you feel like you're the only person unwilling to accept a cult of personality. On days like today you fully realize there are more of us than there are them. You will feel better.

Trainings ahead of Saturday's #NoKings events - know your rights and learn what to do if non-peaceful outside agitators start instigating ruckus: www.nokings.org/trainings

Washtenaw folks: Milan has a few Flock license plate reading cameras installed, and Ypsilanti Township had considered installing hundreds of them with the support of the previous Sheriff. www.404media.co/ice-taps-int...

Picked this book up on a whim at Vault of Midnight, and had so much fun with my 11-year-old making our first batch of dumplings together. I wish more kids cookbooks were written like graphic novels!

Hire him while you can

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.

Get your lawn sign supporting the new downtown library branch proposals supportaadl.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...

It's agent.perflab.io update time! I've been busy getting the artifacts generation in proper order, getting them ready for DB storage ▲ Got some inspo on how to better handle artifacts from @aisdk and @vercel chat-sdk template: chat-sdk.dev/docs/customi.... youtu.be/e-Ie_2D4iR8