Reminder: ticket prices will go up by €100 + VAT this Wednesday, 1st of July. There are a few cheap tickets left. We also announced @patmeenan.com, @stephaniewalter.bsky.social and @programmingart.bsky.social (MC). perfnow.nl/tickets.html

📢 Tomorrow will be H2 protocol's anniversary. With multiplexing, updated header compression and more, H/2 was a timely arrival. To discuss the arrival of H2, we are joined by none other than @programmingart.bsky.social expet in web protocols! 📆 May 14TH ⏰ 2PM EDT 🔗 www.youtube.com/live/ZD9vTom...

Happy New Year, folks! The next PerformanceObserver will be in a few weeks on Jan 28 featuring Morgan Murrah and Robin Marx (@programmingart.bsky.social) ! Join us live for access to chat and Q&A - all details and add to calendar at: performanceobserver.dev #webperf

TTFB is a notoriously difficult performance metric, because it has so many different definitions and nuances. New features like Early Hints and Speculation Rules only make that worse. My new blog highlights these issues so you know what to keep in mind: calendar.perfplanet.com/2025/ttfb-do...

Web Performance Calendar day 24 with @programmingart.bsky.social on TTFB. Yes, it's one of those X-mas Eves where we cuddle by the fire, drop everything and immerse into re-learning and re-evaluating what we thought we knew about a concept we use daily calendar.perfplanet.com/2025/ttfb-do...

Halloween at #perfnow, pirates and vampires. A.k.a sword fight, the sequel. Or... How RUMvision slayed Akamai😇😆 (jk)

@programmingart.bsky.social and I are on the same page for a lot of things but I'm still learning from the master on how much drip a Halloween costume should have #perfNow

Compression dictionaries is now an official RFC! www.rfc-editor.org/rfc/rfc9842....

It’s not the whole story, but if you cannot see the truth of this, you need to pay more attention.

Day 011 #100DaysOfPerf: I shared the hpbn book (Day 002) that wall about levelling up on HTTP. Well, let's look at CURRENT HTTP data from the @httparchive.org's Web Almanac. On deck ✨ HTTP ✨ by none other than @programmingart.bsky.social. Let's take a look: 🧵⬇️ almanac.httparchive.org/en/2024/http

Featured posts this week: ⚡ Fast and furious: @catchpointsystems.bsky.social ⚡ How browsers REALLY load Web pages: @programmingart.bsky.social ⚡ Client-Side Rendering: @adevnadia.bsky.social ⚡ More Edge features get a perf boost: Mohamed Mansour Special thanks to the authors.🙏

We kick off with @programmingart.bsky.social showing us how browsers REALLY load web pages to a full room! 🤡 fosdem.org/2025/schedul...

HTTP/1.1/2/3 are all present in unison on the web today, w/ a 21/70/9 split. Or is it? @programmingart.bsky.social will shed the light on the @httparchive.org Web Almanac data, and the reality of the protocol's adoption. Join us to hear him share findings this Thursday 🔗 ⬇️ bsky.app/profile/henr...

Hmm, interesting - looks like Chrome added support for the ORIGIN frame for HTTP/3 (eliminating the need for a DNS lookup before coalescing connections). blog.chromium.org/2024/12/maki...

Web performance calendar day 29 with @patmeenan.com on how to ship a production-quality dictionary compression implementation to reduce HTML/JS/CSS response sizes dramatically (as in 60-90% dramatically!) calendar.perfplanet.com/2024/getting...

Web performance calendar day 21 with @timvereecke.bsky.social giving us the gift of UNO (Unattributed Navigation Overhead) - an insight into the blind spot gaps between TTFB components calendar.perfplanet.com/2024/uno/

For this year's #webperf calendar, I wrote "Top 8️⃣ things I want in the Devtools Network Panel". I often struggle to debug modern networking features in browsers (like DNS HTTPS records, 0-RTT, and Happy Eyeballs 👀) and have some ideas on how to improve that! calendar.perfplanet.com/2024/top-8-t...

My meme-game is on-point for my (first) perfcalendar 2024 submission @stoyan.org!

This year, I again had the honour of authoring the HTTP chapter of the Web Almanac: almanac.httparchive.org/en/2024/http It's full of interesting stats on technologies like HTTP/3, DNS HTTPS records, preloads, 103 Early Hints and the FetchPriority API. It also has Pirates 🏴‍☠️ and Marry Poppins 🌂!

The HTTP chapter was written by @programmingart.bsky.social and being our first name, is a subject close to our heart 😀 almanac.httparchive.org/en/2024/http Read it for lots of fascinating deep dive into to how web resources are delivered and the latest on how developers can influence that!

the blog post writeup of this is so good eieio.games/blog/writing...

Some of you complain that PageSpeed Insights is a bit unrealistically show for the Lighthouse test. The PSI servers are a bit underpowered so we're changing the throttling, which should make the Performance score go up when this rolls out in the next few weeks. github.com/GoogleChrome... 🧵 1/5

It's December 1st, and you know what that means: For the next 24 days, we'll publish articles about HTML by 24 authors. You can read them on the website or subscribe to the RSS channel. Enjoy! htmhell.dev/adventcalend...

My #wls2024 talk is available! I delved into advanced tuning techniques to make a modern website lightning fast. Using lots of charts and data, I showed how they helped make scalemates the fastest (and largest) modeling website in the world. www.youtube.com/watch?v=rjUr... #webperf

My talk from this year's We Love Speed is on YouTube! 👇 In "Tight Mode: how browsers REALLY load web pages", I take a very deep/very nerdy dive into why browsers sometimes intentionally delay loading resources, why they all do it differently, and why they should *stop clowning around* 🤡 #webperf

I've submitted two proposals for this: - How browsers REALLY load web pages - A First Foray into Compression Dictionaries You, dear reader, should also submit something 😉

I've done a lot of research myself exposing inconsistencies in browser/server implementations of "standardized" features. Below is another excellent example of how even cookies are broken to an incomprehensible degree... all without being properly documented. We need to start doing better.

We're excited to share that Mozilla and @wikimedia.bsky.social will once again be hosting a #webperf devroom at @fosdem.bsky.social 2025! The call for participation is open until December 1st. Find details on how to submit your proposal at wiki.mozilla.org/Performance/... #fosdem #cfp

Fellow #perfnow attendee, the PerfPlanet advent calendar is looking for articles for the 2024 edition. Please come talk to me if you’re considering an idea for a post but you’re not sure and you need a second opinion calendar.perfplanet.com/contribute/

@programmingart.bsky.social now on stage talking about #webperf tools

Anyone interested in seeing how Compression dictionaries work for your dynamic content (live)? I'm experimenting with a Cloudflare worker that can proxy a site and apply a compression dictionary to the document responses. For example, CNN HTML payloads are 50-65% smaller: cnn.patrickmeenan.com

Planet Performance Calendar is a one-article-a-day Advent -style publication that runs in December since 2009, focused on Web Performance. If you (or anyone you know) want to share your experience, tool, research, rant with the #webperf community, please reach out calendar.perfplanet.com/contribute/

Trump has relentlessly attacked trans people throughout his campaign. Will Vercel and Next.js distance themselves from his repugnant comments?

In case you missed it, this episode of JavaScript Jabber podcast with @programmingart.bsky.social about Web network and protocol performance was awesome! www.youtube.com/live/kZXAbN0... #webperf

My full post history is back on twitter (x.com/programmingart), but in case you're struggling to remember where you might know me from, it's likely from this article series on HTTP/3 and QUIC (and other content on Web performance and protocols) :)

I'm building a web perf starter pack but I'm still looking for folks to add - please let me know who I'm missing because I haven't found them all on bsky yet go.bsky.app/RVWSVqe