John Allsopp
@johnfallsopp.com
Great grand father of responsive web design. Web Daoist. Organiser of the Web Directions conferences webdirections.org
Built the streaming service for conferences conffab.com
post clips to Bluesky from any webpage webdirections.org/bluesky-poster
Built the streaming service for conferences conffab.com
post clips to Bluesky from any webpage webdirections.org/bluesky-poster
Reposted by John Allsopp
Kicking off the Perf Calendar 2025 is
@mb21.bsky.social :
✨ Improve TTFB and UX with HTTP streaming ✨
calendar.perfplanet.com/2025/improve...
@mb21.bsky.social :
✨ Improve TTFB and UX with HTTP streaming ✨
calendar.perfplanet.com/2025/improve...
Improve TTFB and UX with HTTP streaming
If you have a statically generated website hosted on a CDN, it’s probably very fast (unless you add too much client-side JavaScript).
However, for dynamically generated pages that load content from a...
calendar.perfplanet.com
December 1, 2025 at 10:28 PM
Kicking off the Perf Calendar 2025 is
@mb21.bsky.social :
✨ Improve TTFB and UX with HTTP streaming ✨
calendar.perfplanet.com/2025/improve...
@mb21.bsky.social :
✨ Improve TTFB and UX with HTTP streaming ✨
calendar.perfplanet.com/2025/improve...
New purchase. Book club?
December 2, 2025 at 12:00 AM
New purchase. Book club?
The Folks at @opensource.block.xyz have an advent of AI, a series of challenges over the next three weeks to work with Goose to solve practical programming challenges that's just kicked off.
adventofai.dev
adventofai.dev
Advent of AI
An advent calendar of AI engineering challenges. Learn goose by building real projects from CI automation to multi-agent orchestration.
adventofai.dev
December 1, 2025 at 9:15 PM
The Folks at @opensource.block.xyz have an advent of AI, a series of challenges over the next three weeks to work with Goose to solve practical programming challenges that's just kicked off.
adventofai.dev
adventofai.dev
Reposted by John Allsopp
📢 WebGPU is now officially supported across Chrome, Edge, Firefox, and Safari → goo.gle/3MmN7Rj
Access high-performance 3D graphics and AI capabilities right in the browser with this major milestone.
Access high-performance 3D graphics and AI capabilities right in the browser with this major milestone.
December 1, 2025 at 5:00 PM
📢 WebGPU is now officially supported across Chrome, Edge, Firefox, and Safari → goo.gle/3MmN7Rj
Access high-performance 3D graphics and AI capabilities right in the browser with this major milestone.
Access high-performance 3D graphics and AI capabilities right in the browser with this major milestone.
Reposted by John Allsopp
December is here (in a few hours in my timezone), which means the Web Performance "Advent" Calendar is back for its... 17th Edition! One article a day in the month of December.
Be a part of it and contribute an article: calendar.perfplanet.com/contribute/
Be a part of it and contribute an article: 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
December 1, 2025 at 4:06 AM
December is here (in a few hours in my timezone), which means the Web Performance "Advent" Calendar is back for its... 17th Edition! One article a day in the month of December.
Be a part of it and contribute an article: calendar.perfplanet.com/contribute/
Be a part of it and contribute an article: calendar.perfplanet.com/contribute/
Reposted by John Allsopp
The Bureau of Meteorology (AU)'s new website cost $96.5m and performs slightly worse than the old one.
LCP & CLS both degraded.
calibreapp.com/tools/core-w...
LCP & CLS both degraded.
calibreapp.com/tools/core-w...
calibreapp.com
December 1, 2025 at 6:42 AM
The Bureau of Meteorology (AU)'s new website cost $96.5m and performs slightly worse than the old one.
LCP & CLS both degraded.
calibreapp.com/tools/core-w...
LCP & CLS both degraded.
calibreapp.com/tools/core-w...
Reposted by John Allsopp
three years ago today ChatGPT launched. so i wrote about its legacy (for now). (turns out a whole hell
of a lot happened in just 3 years) www.theatlantic.com/technology/2...
of a lot happened in just 3 years) www.theatlantic.com/technology/2...
The World Still Hasn’t Made Sense of ChatGPT
OpenAI’s chaos machine turns three.
www.theatlantic.com
November 30, 2025 at 7:07 PM
three years ago today ChatGPT launched. so i wrote about its legacy (for now). (turns out a whole hell
of a lot happened in just 3 years) www.theatlantic.com/technology/2...
of a lot happened in just 3 years) www.theatlantic.com/technology/2...
Reposted by John Allsopp
The truth about #AI and developer jobs... It's not what you think! 👀
Perhaps ZIRP is more to blame for tech layoffs than AI?
Check out the most recent @overcommitted.dev episode with @kateholterhoff.com for more!
Perhaps ZIRP is more to blame for tech layoffs than AI?
Check out the most recent @overcommitted.dev episode with @kateholterhoff.com for more!
December 1, 2025 at 12:34 AM
The truth about #AI and developer jobs... It's not what you think! 👀
Perhaps ZIRP is more to blame for tech layoffs than AI?
Check out the most recent @overcommitted.dev episode with @kateholterhoff.com for more!
Perhaps ZIRP is more to blame for tech layoffs than AI?
Check out the most recent @overcommitted.dev episode with @kateholterhoff.com for more!
Reposted by John Allsopp
Here’s a question I get a lot:
> “Now that AI can generate front-end UIs for us, what’s the point of learning CSS ourselves?”
I think there are lots of reasons, including that you can use AI much more effectively if you understand CSS yourself.
But is that actually true? Let’s discuss. 🧵
> “Now that AI can generate front-end UIs for us, what’s the point of learning CSS ourselves?”
I think there are lots of reasons, including that you can use AI much more effectively if you understand CSS yourself.
But is that actually true? Let’s discuss. 🧵
November 30, 2025 at 4:31 PM
Here’s a question I get a lot:
> “Now that AI can generate front-end UIs for us, what’s the point of learning CSS ourselves?”
I think there are lots of reasons, including that you can use AI much more effectively if you understand CSS yourself.
But is that actually true? Let’s discuss. 🧵
> “Now that AI can generate front-end UIs for us, what’s the point of learning CSS ourselves?”
I think there are lots of reasons, including that you can use AI much more effectively if you understand CSS yourself.
But is that actually true? Let’s discuss. 🧵
Reposted by John Allsopp
Point 2 here is very true
I think where I’m starting to land, with my experienced pre and post coding agents:
1. This is true, coding agents make you more productive if you know how to use them.
2. MBAs hoping coding agents will replace coders wholesale are going to be very disappointed with the results if they try.
1. This is true, coding agents make you more productive if you know how to use them.
2. MBAs hoping coding agents will replace coders wholesale are going to be very disappointed with the results if they try.
At the risk of starting the flame war to end all flame wars...
Modern LLMs (GPT-5.1, Claude 4.5, Gemini 3) produce excellent code and can be a significant productivity boost to software engineers who take the time to learn how to effectively apply them - especially if used with coding agent tools
Modern LLMs (GPT-5.1, Claude 4.5, Gemini 3) produce excellent code and can be a significant productivity boost to software engineers who take the time to learn how to effectively apply them - especially if used with coding agent tools
November 30, 2025 at 6:08 PM
Point 2 here is very true
Reposted by John Allsopp
Out of curiosity I decided to try and run the numbers on how much Netflix you can watch for the energy cost of a ChatGPT prompt
As far as I can tell it's between 5.1 and 10.2 seconds, depending on which end of the 2019 IEA Netflix energy usage estimate you use
simonwillison.net/2025/Nov/29/...
As far as I can tell it's between 5.1 and 10.2 seconds, depending on which end of the 2019 IEA Netflix energy usage estimate you use
simonwillison.net/2025/Nov/29/...
November 29, 2025 at 2:16 AM
Out of curiosity I decided to try and run the numbers on how much Netflix you can watch for the energy cost of a ChatGPT prompt
As far as I can tell it's between 5.1 and 10.2 seconds, depending on which end of the 2019 IEA Netflix energy usage estimate you use
simonwillison.net/2025/Nov/29/...
As far as I can tell it's between 5.1 and 10.2 seconds, depending on which end of the 2019 IEA Netflix energy usage estimate you use
simonwillison.net/2025/Nov/29/...
Reposted by John Allsopp
Starting today and through the weekend I’m offering a discount on Testing Accessibility, my course on web accessibility. Check it out and get 50% off! testingaccessibility.com/buy
Buy Testing Accessibility
Learn how to build and test accessible web applications with Marcy Sutton.
testingaccessibility.com
November 28, 2025 at 4:17 PM
Starting today and through the weekend I’m offering a discount on Testing Accessibility, my course on web accessibility. Check it out and get 50% off! testingaccessibility.com/buy
Reposted by John Allsopp
The classic Breadcrumb Navigation using the below technique.
Demo: codepen.io/t_afif/full/... via @codepen.io
Demo: codepen.io/t_afif/full/... via @codepen.io
November 27, 2025 at 7:53 PM
The classic Breadcrumb Navigation using the below technique.
Demo: codepen.io/t_afif/full/... via @codepen.io
Demo: codepen.io/t_afif/full/... via @codepen.io
Reposted by John Allsopp
A *huge* vaccine victory. I've been writing on this for years; Australia has seen remarkable progress in cervical cancer prevention with the HPV vaccine. I love seeing science triumph like this.
Australia recorded ZERO cases of cervical cancer in women under 25 for the first time since they started tracking the cancer in the 80s.
This is the power of vaccines.
The HPV vaccine is extremely effective at preventing cancer.
Viruses can be oncogenic. Get your vaccines and protect yourself!
This is the power of vaccines.
The HPV vaccine is extremely effective at preventing cancer.
Viruses can be oncogenic. Get your vaccines and protect yourself!
newsGP - Australia set for world-first cervical cancer elimination
Vaccination programs have played a key role, and GPs remain ‘instrumental’ in boosting screening rates to reach the 2035 target.
www1.racgp.org.au
November 27, 2025 at 6:12 PM
A *huge* vaccine victory. I've been writing on this for years; Australia has seen remarkable progress in cervical cancer prevention with the HPV vaccine. I love seeing science triumph like this.
Reposted by John Allsopp
At the risk of starting the flame war to end all flame wars...
Modern LLMs (GPT-5.1, Claude 4.5, Gemini 3) produce excellent code and can be a significant productivity boost to software engineers who take the time to learn how to effectively apply them - especially if used with coding agent tools
Modern LLMs (GPT-5.1, Claude 4.5, Gemini 3) produce excellent code and can be a significant productivity boost to software engineers who take the time to learn how to effectively apply them - especially if used with coding agent tools
November 27, 2025 at 7:55 PM
At the risk of starting the flame war to end all flame wars...
Modern LLMs (GPT-5.1, Claude 4.5, Gemini 3) produce excellent code and can be a significant productivity boost to software engineers who take the time to learn how to effectively apply them - especially if used with coding agent tools
Modern LLMs (GPT-5.1, Claude 4.5, Gemini 3) produce excellent code and can be a significant productivity boost to software engineers who take the time to learn how to effectively apply them - especially if used with coding agent tools
Reposted by John Allsopp
Lots of course creators are running Black Friday sales. I’ve been making notes about some of the most compelling offers, and I have a list of 10 *fantastic* deals. I’ll be sending a newsletter issue about it tomorrow. 😄
Have you scored any great Black Friday deals? Anything I should include?
Have you scored any great Black Friday deals? Anything I should include?
Join my newsletter! • Josh W. Comeau
Friendly tutorials for developers. Focus on React, CSS, Animation, and more!
www.joshwcomeau.com
November 27, 2025 at 7:47 PM
Lots of course creators are running Black Friday sales. I’ve been making notes about some of the most compelling offers, and I have a list of 10 *fantastic* deals. I’ll be sending a newsletter issue about it tomorrow. 😄
Have you scored any great Black Friday deals? Anything I should include?
Have you scored any great Black Friday deals? Anything I should include?
Reposted by John Allsopp
Hey, if you happen to be celebrating a holiday this weekend, why not spend some time building your own MCP server?
Ok there's probably plenty of reasons.
But if you're bored maybe give it a try? Here's how I did it. blog.damato.design/posts/minefi...
Ok there's probably plenty of reasons.
But if you're bored maybe give it a try? Here's how I did it. blog.damato.design/posts/minefi...
Minefield Context Protocol
Being ahead of the curve can make you a pawn on the field.
blog.damato.design
November 27, 2025 at 6:37 PM
Hey, if you happen to be celebrating a holiday this weekend, why not spend some time building your own MCP server?
Ok there's probably plenty of reasons.
But if you're bored maybe give it a try? Here's how I did it. blog.damato.design/posts/minefi...
Ok there's probably plenty of reasons.
But if you're bored maybe give it a try? Here's how I did it. blog.damato.design/posts/minefi...
Reposted by John Allsopp
Always nice to get a shoutout at the start of a @joshwcomeau.com article!
This one's on subgrid. If you haven't been using it yet, as you'd expect, it's great, and you should give it a read 🙂
www.joshwcomeau.com/css/subgrid/
This one's on subgrid. If you haven't been using it yet, as you'd expect, it's great, and you should give it a read 🙂
www.joshwcomeau.com/css/subgrid/
Brand New Layouts with CSS Subgrid • Josh W. Comeau
Subgrid allows us to extend a grid template down through the DOM tree, so that deeply-nested elements can participate in the same grid layout. At first glance, I thought this would be a helpful conven...
www.joshwcomeau.com
November 25, 2025 at 6:13 PM
Always nice to get a shoutout at the start of a @joshwcomeau.com article!
This one's on subgrid. If you haven't been using it yet, as you'd expect, it's great, and you should give it a read 🙂
www.joshwcomeau.com/css/subgrid/
This one's on subgrid. If you haven't been using it yet, as you'd expect, it's great, and you should give it a read 🙂
www.joshwcomeau.com/css/subgrid/
Reposted by John Allsopp
The new MCP spec just dropped! 🎉
There's too many new things to get into everything, but there are two big changes I am most excited about 👀
📝 Client ID Metadata Documents (CIMD) - a simpler way to manage client registrations, clients describe themselves with a URL they control
There's too many new things to get into everything, but there are two big changes I am most excited about 👀
📝 Client ID Metadata Documents (CIMD) - a simpler way to manage client registrations, clients describe themselves with a URL they control
November 25, 2025 at 11:14 PM
The new MCP spec just dropped! 🎉
There's too many new things to get into everything, but there are two big changes I am most excited about 👀
📝 Client ID Metadata Documents (CIMD) - a simpler way to manage client registrations, clients describe themselves with a URL they control
There's too many new things to get into everything, but there are two big changes I am most excited about 👀
📝 Client ID Metadata Documents (CIMD) - a simpler way to manage client registrations, clients describe themselves with a URL they control
This is the best advertisement for the mobile Web ever!
www.instagram.com/reel/DRZAR8e...
This will bring a tear to the eye of @infrequently.org, and @brucelawson.vivaldi.net.ap.brid.gy
www.instagram.com/reel/DRZAR8e...
This will bring a tear to the eye of @infrequently.org, and @brucelawson.vivaldi.net.ap.brid.gy
Fairbairn Films on Instagram: "When you have to download a new app
Follow us @lachlanfairbairn and @jaxonfairbairn"
In this entertaining and relatable video, two brothers experience the frustrations of downloading new apps and the consequences of not having them. They discuss the convenience and usability of apps, ...
www.instagram.com
November 25, 2025 at 10:40 PM
This is the best advertisement for the mobile Web ever!
www.instagram.com/reel/DRZAR8e...
This will bring a tear to the eye of @infrequently.org, and @brucelawson.vivaldi.net.ap.brid.gy
www.instagram.com/reel/DRZAR8e...
This will bring a tear to the eye of @infrequently.org, and @brucelawson.vivaldi.net.ap.brid.gy
via @ajfisher.social I recently learned about three-sided football, and it might sound like a trivial change to the game of football. Turns out it has really interesting implications.
en.wikipedia.org/wiki/Three-s...
en.wikipedia.org/wiki/Three-s...
Three-sided football - Wikipedia
en.wikipedia.org
November 25, 2025 at 9:01 PM
via @ajfisher.social I recently learned about three-sided football, and it might sound like a trivial change to the game of football. Turns out it has really interesting implications.
en.wikipedia.org/wiki/Three-s...
en.wikipedia.org/wiki/Three-s...
my iPhone 13 cracked screen and all continues to serve me just fine. My 4 teenage daughters have yet to upgrade to ios26 (as have I)–a new iOS version used not long ago for them to be a cause of considerable excitement.
And they and their friends are at bat meh on AI generated images, videos etc
And they and their friends are at bat meh on AI generated images, videos etc
November 25, 2025 at 8:57 PM
my iPhone 13 cracked screen and all continues to serve me just fine. My 4 teenage daughters have yet to upgrade to ios26 (as have I)–a new iOS version used not long ago for them to be a cause of considerable excitement.
And they and their friends are at bat meh on AI generated images, videos etc
And they and their friends are at bat meh on AI generated images, videos etc
Reposted by John Allsopp
Reposted by John Allsopp
oh it’s “hoarding” now if you don’t update your expensive electronics every year
November 25, 2025 at 8:39 PM
oh it’s “hoarding” now if you don’t update your expensive electronics every year