Robin Marx
@programmingart.bsky.social
Network protocols (HTTP/2, HTTP/3, QUIC) and Web performance
at Akamai. PhD. Dad. Longsword fencer. He/Him.
http://linkedin.com/in/rmarx
@[email protected]
at Akamai. PhD. Dad. Longsword fencer. He/Him.
http://linkedin.com/in/rmarx
@[email protected]
Pinned
Robin Marx
@programmingart.bsky.social
· Oct 30
HTTP/3 From A To Z: Core Concepts — Smashing Magazine
What exactly is HTTP/3? Why was it needed so soon after HTTP/2 (which was only finalized in 2015)? How can or should you use it? And especially, how does this improve web performance? Let’s find out.
www.smashingmagazine.com
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) :)
Reposted by Robin Marx
@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
October 31, 2025 at 10:51 AM
@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
Reposted by Robin Marx
Compression dictionaries is now an official RFC! www.rfc-editor.org/rfc/rfc9842....
RFC 9842: Compression Dictionary Transport
This document specifies a mechanism for dictionary-based compression in the
Hypertext Transfer Protocol (HTTP). By utilizing this technique, clients and
servers can reduce the size of transmitted data...
www.rfc-editor.org
October 1, 2025 at 5:56 AM
Compression dictionaries is now an official RFC! www.rfc-editor.org/rfc/rfc9842....
Reposted by Robin Marx
It’s not the whole story, but if you cannot see the truth of this, you need to pay more attention.
September 30, 2025 at 12:47 AM
It’s not the whole story, but if you cannot see the truth of this, you need to pay more attention.
Reposted by Robin Marx
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
almanac.httparchive.org/en/2024/http
March 16, 2025 at 11:40 PM
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
almanac.httparchive.org/en/2024/http
Reposted by Robin Marx
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.🙏
⚡ 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.🙏
February 23, 2025 at 3:32 PM
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.🙏
⚡ 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.🙏
Reposted by Robin Marx
We kick off with @programmingart.bsky.social showing us how browsers REALLY load web pages to a full room! 🤡 fosdem.org/2025/schedul...
February 1, 2025 at 2:14 PM
We kick off with @programmingart.bsky.social showing us how browsers REALLY load web pages to a full room! 🤡 fosdem.org/2025/schedul...
Reposted by Robin Marx
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...
🔗 ⬇️
bsky.app/profile/henr...
January 13, 2025 at 5:11 PM
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...
🔗 ⬇️
bsky.app/profile/henr...
Reposted by Robin Marx
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...
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
January 6, 2025 at 8:17 PM
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...
blog.chromium.org/2024/12/maki...
Reposted by Robin Marx
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...
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
December 30, 2024 at 2:10 AM
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...
calendar.perfplanet.com/2024/getting...
Reposted by Robin Marx
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/
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
December 21, 2024 at 5:39 PM
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/
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...
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
December 16, 2024 at 4:02 PM
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...
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!
December 10, 2024 at 10:30 PM
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 🌂!
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
December 10, 2024 at 12:37 PM
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 🌂!
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 🌂!
Reposted by Robin Marx
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!
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
December 10, 2024 at 11:28 AM
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!
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!
Reposted by Robin Marx
the blog post writeup of this is so good eieio.games/blog/writing...
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!
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!
December 7, 2024 at 1:10 PM
the blog post writeup of this is so good eieio.games/blog/writing...
Reposted by Robin Marx
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
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
December 5, 2024 at 4:36 PM
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
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
Reposted by Robin Marx
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...
Enjoy!
htmhell.dev/adventcalend...
HTMHell Advent Calendar 2024 - HTMHell
An article, talk, or tool that focuses on HTML every day until Christmas.
htmhell.dev
December 1, 2024 at 8:00 AM
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...
Enjoy!
htmhell.dev/adventcalend...
Reposted by Robin Marx
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
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
www.youtube.com
November 27, 2024 at 8:15 AM
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
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
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
www.youtube.com
November 26, 2024 at 10:09 AM
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
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 😉
- How browsers REALLY load web pages
- A First Foray into Compression Dictionaries
You, dear reader, should also submit something 😉
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 :)
FOSDEM 2025 - Call for Participation - MozillaWiki
wiki.mozilla.org
November 25, 2024 at 2:56 PM
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 😉
- 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.
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..
I doesn't seem there are easy solutions here..
April King — Handling Cookies is a Minefield
Discrepancies in how browsers and libraries handle HTTP cookies, and the problems caused by such things.
grayduck.mn
November 25, 2024 at 12:56 PM
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.
Reposted by Robin Marx
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
FOSDEM 2025 - Call for Participation - MozillaWiki
wiki.mozilla.org
November 18, 2024 at 12:37 PM
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
Reposted by Robin Marx
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 [email protected]. Please include:
...
calendar.perfplanet.com
November 14, 2024 at 11:21 AM
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/
Reposted by Robin Marx
November 13, 2024 at 1:26 PM