Finally, a CLI/module for testing compression dictionary deployments: blog.patrickmeenan.com/2026/07/26/t... Thanks to @programmingart.bsky.social @sergeyche.dev and @yoav.ws for not letting me continue to ignore building it 😂

Testing Compression Dictionary Deployments - Patrick Meenan's Blog

Robin Marx has been asking me for a Compression Dictionary Transport (RFC 9842) test tool for a long time (since well before AI was actually useful for this...

blog.patrickmeenan.com

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

performance.now(); 19th and 20th of November 2026, Amsterdam

On 19th and 20th of November 2026, the seventh edition of performance.now() will take place in Amsterdam—a single track conference, covering today’s most important web performance insights.

perfnow.nl

📢 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

PerformanceObserver: A virtual web perf meetup

Join the PerformanceObserver virtual performance meetup to get all the latest web performance news and hang out with the community.

performanceobserver.dev

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...

TTFB doesn't mean what you think it means

Time-To-First-Byte (TTFB) is a popular performance metric, yet there are many problems and nuances with it. Not only does it have several different definitions, it is usually also a "compound" metric,...

calendar.perfplanet.com

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...

TTFB doesn't mean what you think it means

Time-To-First-Byte (TTFB) is a popular performance metric, yet there are many problems and nuances with it. Not only does it have several different definitions, it is usually also a "compound" metric,...

calendar.perfplanet.com

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.

JB_AU@jbau.bsky.social · 10mo ago

This whole section really.

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...

Henri Helvetica 🧑🏾‍🚀🇭🇹@henrihelvetica.bsky.social · 2y ago

🎙️ New year, more new content. We are continuing to explore data + content w/ the next stream: ✨ The Web Almanac LIVE STREAM II ✨ @httparchive.org Web Almanac discussions will include: SEO, Privacy, HTTP, Cookies + 3rd Parties. Join us for this discussion + Q&A! 🔗: www.youtube.com/live/zCiMls2...

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...

Making Chrome QUICer

In October 2020, Chrome enabled HTTP/3 by default . HTTP/3 ( RFC 9114 ) runs over IETF QUIC ( RFC9000 ). Default-enabling HTTP/3 in Chrome ...

blog.chromium.org

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...

Getting Real (small) With Compression Dictionaries

Compression dictionary transport is a relatively new feature in HTTP that allows for using custom compression dictionaries to improve the compression of HTTP responses. The results can be pretty drama...

calendar.perfplanet.com

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/

Unattributed Navigation Overhead (UNO)

I promise you, UNO (Unattributed Navigation Overhead) is the best Christmas present you will get this year! UNO, not the card game, is the missing piece for many of your unsolved performance puzzles...

calendar.perfplanet.com

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...

Top 8 things I want in the Devtools Network Panel

Look, I'm just going to come out and say it: I'm a jealous man. I'm not proud of it, but I'm a jealous man. These past months and years, I've seen great update after amazing update (not you) being rel...

calendar.perfplanet.com

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 🌂!

HTTP | 2024 | The Web Almanac by HTTP Archive

The HTTP chapter of the 2024 Web Almanac covers data on historical versions of HTTP used across the web, as well as the uptick in adoption of HTTP/2 and HTTP/3 from alt-svc and DNS HTTPS records. Addi...

almanac.httparchive.org

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!

HTTP | 2024 | The Web Almanac by HTTP Archive

The HTTP chapter of the 2024 Web Almanac covers data on historical versions of HTTP used across the web, as well as the uptick in adoption of HTTP/2 and HTTP/3 from alt-svc and DNS HTTPS records. Addi...

almanac.httparchive.org

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

nolen@itseieio.bsky.social · 2y ago

how do you all remember every UUID? I find it really hard. so I wrote them all down on every uuid dot com the list has fast search across all 2^122 values (so you can find your favorites) - hoping to add some social features like "trending UUIDs" soon!

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

Release v12.2.3 · GoogleChrome/lighthouse

Full Changelog This release is only for PageSpeed Insights and we expect it to ship within 2 weeks. Notable Changes The CPU throttling factor for PageSpeed Insights has been adjusted (#16256) to ac...

github.com

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...

HTMHell Advent Calendar 2024 - HTMHell

An article, talk, or tool that focuses on HTML every day until Christmas.

htmhell.dev

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

Beyond the basics, pushing the limits of webperf — Tim Vereecke

YouTube video by We Love Speed

youtube.com

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

How browsers REALLY load Web pages — Robin Marx

YouTube video by We Love Speed

youtube.com

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 😉

Peter Hedenskog@peterhedenskog.com · 2y ago

Sunday the 1st of December is the last day to apply for speaking at the Web Performance devroom at FOSDEM: wiki.mozilla.org/Performance/... - the devroom will take place February 1st! Hope to see you there :)

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.

Yoav Weiss@yoav.ws · 2y ago

Great post by @april.social on client- and server-side interop issues with cookies: grayduck.mn/2024/11/21/h... I doesn't seem there are easy solutions here..

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/

Contribute

Passionate about a topic? Working on a new tool? Have a technique you want to teach? Research you've done? Tell the web performance community! Send your articles to ssttoo@ymail.com. Please include: ...

calendar.perfplanet.com