Conference organising in 2026

quirksmode.org/quirksblog/a...

They will be published on YouTube in conjunction with the 2026 ticket sales, which will likely start in May.

2025 conference photos are up

perfnow.nl/2025/pix/pho...

(though I need to consult a speculation rules expert at some point)

Web Conferences Amsterdam We curate and organise deep-diving, single-track, content-focused web conferences, in Amsterdam. Most sessions, about 45 minutes each, include a Q&A session with the speaker. We aim to cover technique...

And the performance.sync() videos, the Wednesday pre-party, are also live. www.youtube.com/@WebConferen...

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.

Team photos are up.

perfnow.nl/teams-2025.h...

This was performance.now() 2025 YouTube video by Web Conferences Amsterdam

A little aftermovie to whet your appetite.

www.youtube.com/watch?v=ByOC...

... maar wat is het probleem ... ?

PerfNow25 - Big Data, Zero JS: Cross-Browser Virtual scrolling Big Data, Zero JS Cross-Browser Virtual Scrolling CONTAIN & CONTENT-VISIBILITY

Here you go! My first perf now as a speaker… it’s was amazing 🤩

docs.google.com/presentation...

I shilled a javascript framework at a web perf conference and came out mostly unscathed, AMA

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

Rich Harris standing on a stage with a large screen behind him showing his live demo

Unsurprising revelation from #perfnow:

@rich-harris.dev really is ruddy good at demonstrating interesting concepts.

His @svelte.dev is demo is terribly compelling.

"Family. The #webperf community is family."
- Dom Toretto

@rich-harris.dev #PerfNow

@rich-harris.dev might have the best demo app I have ever seen 😁 at #perfNow

A speaker is presenting at the performance.now() 2025 conference in front of a large audience. The slide projected behind them reads “SSR is about SEO performance,” with “SEO” crossed out and “performance” emphasized in red.

"SSR is about ~SEO~ performance" - @rich-harris.dev

#perfnow #WebPerf

#perfnow absolutely fantastic and compelling demos from @rich-harris.dev but I'm trying to resist concerns on his preference for tabs over spaces...😂

@perfnow.nl for whoever asked that question about Sec-Purpose it DOES get set on sub-resources for prerendered speculations. Not just the document. #perfnow

It’s an honor to see my company #speedkit mentioned on stage at #perfnow by a web performance VIP and ambassador such as Barry @tunetheweb.com Pollard. 😊 Congrats to the Speed Kit team who implemented speculation rules in such an effective way in our product!

Making Sense of LoAF by Andy Davies Over time the web has become more reliant on JavaScript… but we’ve very little information on how its growth is affecting our visitors’ experience.

Making Sense of Long Animation Frames…

The slides from my #PerfNow talk are available on Notist

noti.st/andydavies/9...

Web Performance Allies - PerfNow 2025 Image credits: https://commons.wikimedia.org/wiki/File:TAR_Detour_clue.png https://commons.wikimedia.org/wiki/File:Carach_Angren_M%C3%A9an_22_08_200…

Here are mine: speakerdeck.com/ethangardner...

How to Think Like a Performance Engineer As awareness and tooling around site speed have been improving at a very exciting rate, has performance testing actually become any easier? Any more str…

speakerdeck.com/csswizardry/...

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/...

#PerfNow has incredibly interesting talks. Anyone who's serious about performance should join.
Proud that we at @framer.com are sponsors.

Accessibility& Performance - perfNow 2025 - Marcy Sutton Todd Accessibility & Performance performance.now() 2025 By Marcy Sutton Todd - Senior Engineer, Frontend Infrastructure at Khan Academy Hi, PerfNow! I'm here to talk to you about the intersection of access...

Here are mine! Thanks for a wonderful conference 🫶🏻 bit.ly/a11y-perfnow25

Always, always happy to see @yoav.ws get a shout-out. So much incredible work has happened because of him. Most recent example—speculation rules in WebKit. #perfnow

Super talk from @tunetheweb.com on Speculation Rules. Been nervous about using them for fear of false positives on things like Google Analytics. The upcoming prerender_until_script logic sounds like exactly what I need - you'll benefit from fetching subresources, but won't execute scripts.

#PerfNow

@marcysutton.com @mmocny.com @andydavies.me @ethangardner.com @inesakrap.bsky.social @csswizardry.com @michael-hladky.bsky.social @adevnadia.bsky.social

Could you please post a link to your conference slides so we can share it with our audience? Thanks!

Stubborn Empathy by Tim Kadlec One of the most important roles we play on the web is as the users line of defense, which requires that we demonstrate stubborn empathy on their behalf. Unfortunately, that concept is all too easy to ...

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...

A speaker in front of a stage, presenting a graph of Time to First Byte before & after a speculation rules experiment, writeup at https://www.etsy.com/codeascraft/search-prefetching-performance

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/...

A wise man once said...
"Simple to use, progressive enhancement, built in APIs are the best!"
- @tunetheweb.com

Yep, he's onto something. loading=lazy and fetchpriority=high are wonderfully simple 'cheat codes', and some of my favourite additions to the world of #webperf.

#PerfNow

One of my favourite pictures from 2023 #perfnow @tunetheweb.com @andydavies.me