I ❤️ writing these annual wrap-up posts. From broad browser support for key metrics to nuanced metrics for diagnosing issues, 2025 has been filled with huge wins — not just for @speedcurve.com but for our entire #webperf community. Go, us! www.speedcurve.com/blog/2025-we...

IYKYK www.youtube.com/watch?v=BGFt...

If you only have time to do ONE THING to make your site holiday-ready (so you can relax and enjoy the next few days off) it's this: CREATE PERFORMANCE BUDGETS 😀 No code changes required 😀 Literally takes just 1-2 minutes 😀 You get alerts if your pages slow down 👉 www.speedcurve.com/web-performa...

What happens when observability merges with front-end performance monitoring? You get the best of all worlds — performance, reliability, and UX across web and mobile! Join our founder @markzeman.com, CPO @cliffcrocker.bsky.social, and @embrace.io President Andrew Tunall on December 9 to learn more!

It's been almost three years, but CrystalCon, the accessibility conference created from spite, is back. This January, I'm giving you six sessions of content over two days, all made by me. Given the current state of tech and digital accessibility, most sessions will focus on artificial intelligence.

Thanks to all who joined me and @seancdavis.com for our #PixelPalooza fireside chat about how image optimization (and lack thereof) affects your users and your business! And thanks to @remotesynthesis.com for inviting me! I put together some interesting stats here: speakerdeck.com/tammyeverts/...

Unoptimized images are STILL a common problem, and they hurt things like: 🙁 #A11y 🙁 #webperf and #UX metrics like LCP and CLS 🙁 Conversions 🙁 #SEO 🙁 Sustainability I'll be talking about this (and solutions!) today (12:15pm PT / 3:15pm ET) at #PixelPalooza. Get your FREE ticket: lnkd.in/g_N8YFrs

Third parties represent a MASSIVE potential single point of failure for your site. 1. AUDIT & remove unused tags 2. DEFER or load asynchronously 3. TRACK scripts & create #webperf budgets 4. KNOW your SLAs with vendors 5. CREATE a playbook for failures 👉 www.speedcurve.com/web-performa... #ux

If your backend times are slow, that hurts all your other key performance and UX metrics, including Core Web Vitals! Find out how to track your CDN's health and get backend transparency — along with 24 more holiday readiness tips! #corewebvitals #webperf #ux #sitespeed #pagespeed

The "i" in "iPhone" stands for "inequality", late 2025 edition:

#PixelPalooza is coming up this Thursday! This awesome FREE online event covers how to make sure all those helpful images and videos on your site don't hurt #webperf and #a11y. I'm joining @seancdavis.com to talk about the hidden cost of media on the web. Get your ticket 👉 cfe.dev/events/pixel...

⚡Featured posts this week: ✨ AI assistance for performance: @matthiasrohmer.bsky.social ✨ The Web Animation Performance: @citizenofnowhe.re ✨ How Fast Is Fast Enough?: @tammyeverts.com ✨ Performance is about people: @markzeman.com 🙏 Special thanks to the authors! #webperf

Video of my @perfnow.nl keynote is up! In this talk, I challenged the false choice between magic and pragmatism. Don't settle for "fast enough". Instead, aim to create a user experience that's #pragmagical — blending user delight with measurable business impact. conffab.com/presentation...

We're joining forces with @embrace.io! Together we'll give you visibility into how users experience your site and your app, so you can create fast, seamless experiences everywhere! AND you'll be able to tie this back to user engagement and business metrics. Stoked about this huge next step! 😀

I love heatmaps so much! They're the best way to get instant insight into where #webperf issues are lurking across your site. Taking it even further, you also get breakdowns across dimensions like page label, browser, device, and location. *chef's kiss* 👉 www.speedcurve.com/blog/new-hea...

ALSO, hat tip to the Vancouver airport for displaying works by local artists. This piece made my day. #YVR

Also, I hope I’m never too old to get excited like a weird nerdy little kid about waking up at an airport hotel with this view of the tarmac.

I know everyone has been avidly following my progress home from #PerfNow </self-deprecating sarcasm> so I’m happy to say that after 29.5 hours in airports and planes, only 2 more hours till I arrive home! 🎉 🎉 🎉 And yes, if you’re wondering, the long haul in both directions is totally worth it!

Another #PerfNow is over, and I’m already looking forward to next year. Thank you so much to… ❤️ @ppkoch.bsky.social for organizing this amazing event ❤️ @tkadlec.bsky.social & @csswizardry.com for being such delightful co-chairs ❤️ Everyone who attends and brings such wonderful energy!

performance.now() 2026 will take place on 19th and 20th of November 2026. #perfnow.

This was intensely good in person, and the slides are worth your time.

If you are looking for the slides from my PerfNow 2025 talk, Web Performance Allies, they are at speakerdeck.com/ethangardner...

Making Sense of Long Animation Frames… The slides from my #PerfNow talk are available on Notist noti.st/andydavies/9...

When the person who walks your dog is really into Halloween…

This screencap from It’s Always Sunny will never not make me laugh out loud. Thanks @webx.bsky.social! #PerfNow #IYKYK

In fact, many past guests are at @perfnow.nl conference right.(now): @webx.bsky.social (now on stage) @kurtextrem.de @tammyeverts.com @timvereecke.bsky.social @programmingart.bsky.social @cliffcrocker.bsky.social @karlijnlowik.bsky.social + more. Link below: 🎥 bit.ly/spdy-streams #perfNow

Interesting! Etsy implemented speculation rules and got these results: 👍 Time to First Byte on the listing page improved 23.6% 👍 First Contentful Paint improved 20.7% 👍 Largest Contentful Paint improved 21.1% 👍 DOMContentLoaded improved 20.4% #PerfNow #webperf www.etsy.com/codeascraft/...

For those who just watched @tunetheweb.com 's presentation, this is the SPDY STREAM he just posted about w/ @yoav.ws + @krzksz.bsky.social of Shopify. Thank again Barry! #perfNow 🎥 youtu.be/DHgoULxvuJ8

I appreciate everyone at #perfnow letting me have my "old man yells at cloud" moment this morning. Slides are now up: noti.st/tkadlec/3imH...

There's a sight to see, freshly published in time for #PerfNow. Talk by @tunetheweb.com , an excellent walkthrough on how to get the most out of a truly powerful tool www.etsy.com/codeascraft/...

For #PerfNow folks (and other folks who are interested in front-end #webperf)… you should know that @adevnadia.bsky.social has written this amazing resource. www.getwebperf.com

Huge thanks to @andydavies.me for mentioning the LoAF Helpers WebPerf Snippet at @perfnow.nl! Honored to be part of the amazing Web Performance community 🫶 🔗 webperf-snippets.nucliweb.net/Interaction/... #WebPerf #PerfNow #Performance #LoAF #INP #CoreWebVitals

So fortunate to work with this guy. Hard-pressed to find anyone with more knowledge on LoAF than @andydavies.me. That shirt though… #perfnow

@andydavies.me on stage at #PerfNow talking about why identifying INP issues can be like finding a needle in a haystack. Heatmaps (like the one onscreen behind him) can help. Learn more about heatmaps: www.speedcurve.com/blog/new-hea...

@andydavies.me has the receipts to call out how 1st party scripts (NextJS) usage really mess with performance in a real world example at #perfNow

Be aware of "survivor bias" in your metrics. Users having a fast experience will view more pages and have longer sessions. Your RUM data is always inherently biased towards those with fast experiences. @andydavies.me #PerfNow #webperf

Learn more about Total Blocking Duration (TBD), the experimental new metric that @andydavies.me is pioneering. #PerfNow www.speedcurve.com/blog/long-an...

@andydavies.me shares a compelling correlation chart. As LoAF duration gets worse, so does the number of pages visited during a session. #PerfNow

“~200 bytes of JavaScript that can wreck your performance” – @andydavies.me explaining download size doesn’t always correlate to runtime performance at #perfnow #webperf

For #PerfNow folks who want to go even deeper on Long Animation Frames, @andydavies.me wrote the definitive guide. www.speedcurve.com/blog/guide-l...

We’re shipping more and more and more JavaScript. And the problem is only going to get worse as most AI-generated web pages are built on JS frameworks. @speedcurve.com performance expert @andydavies.me at #PerfNow

Cross-browser testing is an act of user advocacy. As much as Chrome has pushed the web forward, if that's all we test we could be missing big gotchas. Meet users wherever they are, no matter the scenario. @timkadlec.bsky.social is crushing it, as the kids are saying these days. #PerfNow #webperf

“We are the user’s line of defence” between automated tools that don’t offer accountability. @tkadlec.bsky.social at #PerfNow

Day 2 at #perfnow I'm going to continue to add notes to my blog through the day stuart-mcmillan.com/blog/webperf...

@tkadlec.bsky.social speaking my language on stage at #perfnow. #stubbornempathy #pragmagical

Good morning and happy Halloween, #PerfNow friends! So excited about Day 2! If you’d like to chat about #webperf and #ux, come chat with @andydavies.me and @cliffcrocker.bsky.social and me from Team @speedcurve.com. And I still have plenty of Halloween goodies! Trick or treat!

Fellow #perfnow fellows, a reminder that PerfPlanet calendar is coming this December for another edition. And it needs YOU. Please ask if you have any contribution ideas or concerns calendar.perfplanet.com/contribute/

Be the interpreter for your non-technical stakeholders. Milliseconds don't mean much to most people, make the data relatable. "Now they get a smoother experience that's over 50% faster." @ethangardner.com on making performance allies. #PerfNow #webperf

@ethangardner.com shares some harsh real user feedback about slow sites that we can use to show non-performance folks why site speed matters. #PerfNow

Sharing raw metrics with stakeholders isn’t enough. Instead, share clear problem statements. @ethangardner.com at #PerfNow