Patrick Meenan
@patmeenan.com
Web performance geek on the Chrome team at Google.
Formerly WebPageTest, Meta, Cloudflare, AOL...
Formerly WebPageTest, Meta, Cloudflare, AOL...
Reposted by Patrick Meenan
Implemented shared compression dictionaries [1] on an @11ty.dev site.
Nothing in production to share yet, but shows HTML responses being ¼–⅓ the size of @netlify.com's dynamic Brotli-compression.
~4-6kb per page inc. inlined CSS, before any tuning 🤯
[1]: chromestatus.com/feature/5124...
#webperf
Nothing in production to share yet, but shows HTML responses being ¼–⅓ the size of @netlify.com's dynamic Brotli-compression.
~4-6kb per page inc. inlined CSS, before any tuning 🤯
[1]: chromestatus.com/feature/5124...
#webperf
Chrome Platform Status
chromestatus.com
November 17, 2025 at 3:35 PM
Implemented shared compression dictionaries [1] on an @11ty.dev site.
Nothing in production to share yet, but shows HTML responses being ¼–⅓ the size of @netlify.com's dynamic Brotli-compression.
~4-6kb per page inc. inlined CSS, before any tuning 🤯
[1]: chromestatus.com/feature/5124...
#webperf
Nothing in production to share yet, but shows HTML responses being ¼–⅓ the size of @netlify.com's dynamic Brotli-compression.
~4-6kb per page inc. inlined CSS, before any tuning 🤯
[1]: chromestatus.com/feature/5124...
#webperf
Reposted by Patrick Meenan
Fellow #perfnow fellows, a reminder that PerfPlanet calendar is coming this December for another edition. And it needs YOU. Please ask if you have any contribution ideas or concerns 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
October 30, 2025 at 4:59 PM
Fellow #perfnow fellows, a reminder that PerfPlanet calendar is coming this December for another edition. And it needs YOU. Please ask if you have any contribution ideas or concerns calendar.perfplanet.com/contribute/
Reposted by Patrick Meenan
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/...
👍 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/...
www.etsy.com
October 31, 2025 at 2:32 PM
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/...
👍 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/...
Reposted by Patrick Meenan
I've been writing more about how Web Standards *actually* come to be, and the responses make me thing there's a ton more to discuss; so in the spirit of figuring it out together, AMA:
infrequently.org/series/effective…
infrequently.org/series/effective…
Effective Standards Work - Infrequently Noted
Alex Russell on browsers, standards, and the process of progress.
infrequently.org
November 2, 2025 at 7:00 PM
I've been writing more about how Web Standards *actually* come to be, and the responses make me thing there's a ton more to discuss; so in the spirit of figuring it out together, AMA:
infrequently.org/series/effective…
infrequently.org/series/effective…
Reposted by Patrick Meenan
Glad to announce that my team at @cloudflare.social released a 1.0.0 version of a cross-browser web performance testing agent that supports
Chrome, Firefox, Safari and Edge.
Thank you to @tkadlec.bsky.social for making it happen and writing most of the code so far!
github.com/cloudflare/t...
Chrome, Firefox, Safari and Edge.
Thank you to @tkadlec.bsky.social for making it happen and writing most of the code so far!
github.com/cloudflare/t...
GitHub - cloudflare/telescope: Cross-browser web performance testing agent
Cross-browser web performance testing agent. Contribute to cloudflare/telescope development by creating an account on GitHub.
github.com
October 30, 2025 at 2:32 PM
Glad to announce that my team at @cloudflare.social released a 1.0.0 version of a cross-browser web performance testing agent that supports
Chrome, Firefox, Safari and Edge.
Thank you to @tkadlec.bsky.social for making it happen and writing most of the code so far!
github.com/cloudflare/t...
Chrome, Firefox, Safari and Edge.
Thank you to @tkadlec.bsky.social for making it happen and writing most of the code so far!
github.com/cloudflare/t...
Reposted by Patrick Meenan
I am at #perfnow the next two days. Drop by the Google help desk if you want to chat about the Devtools MCP server or our performance agent in Devtools.
October 30, 2025 at 8:43 AM
I am at #perfnow the next two days. Drop by the Google help desk if you want to chat about the Devtools MCP server or our performance agent in Devtools.
Reposted by Patrick Meenan
Really excited to be speaking @perfnow.nl this year—my favourite conference run by some of my favourite people!
If you're into web performance (or wanna be!) and like a great conference with a super friendly vibe then pop along to Amsterdam at the end of October. Tickets selling fast!
perfnow.nl
If you're into web performance (or wanna be!) and like a great conference with a super friendly vibe then pop along to Amsterdam at the end of October. Tickets selling fast!
perfnow.nl
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.
perfnow.nl
September 2, 2025 at 6:42 PM
Really excited to be speaking @perfnow.nl this year—my favourite conference run by some of my favourite people!
If you're into web performance (or wanna be!) and like a great conference with a super friendly vibe then pop along to Amsterdam at the end of October. Tickets selling fast!
perfnow.nl
If you're into web performance (or wanna be!) and like a great conference with a super friendly vibe then pop along to Amsterdam at the end of October. Tickets selling fast!
perfnow.nl
Reposted by Patrick Meenan
I put together a whole page of resources and pointers on these topics, and cannot recommend "Life of a Pixel" often or highly enough:
infrequently.org/links/#web-p...
infrequently.org/links/#web-p...
Want to build faster websites? Here's how:
- Learn how browsers parse, layout & paint
- Treat JS as a tool, not the foundation(!)
- Favor static HTML or server side rendering at all times
- Use Core Web Vitals alongside other metrics to learn shortfalls, improve and iterate
Then keep doing that.
- Learn how browsers parse, layout & paint
- Treat JS as a tool, not the foundation(!)
- Favor static HTML or server side rendering at all times
- Use Core Web Vitals alongside other metrics to learn shortfalls, improve and iterate
Then keep doing that.
August 19, 2025 at 7:09 AM
I put together a whole page of resources and pointers on these topics, and cannot recommend "Life of a Pixel" often or highly enough:
infrequently.org/links/#web-p...
infrequently.org/links/#web-p...
Reposted by Patrick Meenan
"How is it possible for CrUX to say 90% of page loads are good, and Google Search Console to say only 50% of URLs are good. Which is right?"
It's a question I get about Core Web Vitals and I admit it's confusing, but the truth is both are correct because they are different measures...
1/5 🧵
It's a question I get about Core Web Vitals and I admit it's confusing, but the truth is both are correct because they are different measures...
1/5 🧵
August 19, 2025 at 10:32 AM
"How is it possible for CrUX to say 90% of page loads are good, and Google Search Console to say only 50% of URLs are good. Which is right?"
It's a question I get about Core Web Vitals and I admit it's confusing, but the truth is both are correct because they are different measures...
1/5 🧵
It's a question I get about Core Web Vitals and I admit it's confusing, but the truth is both are correct because they are different measures...
1/5 🧵
Fun times when the AI support chatbot hallucinates ACTUALLY placing an order for a replacement item that didn't get delivered.
The actual conversation feels completely effortless until days later when you figure it out because it still hasn't arrived.
The actual conversation feels completely effortless until days later when you figure it out because it still hasn't arrived.
August 7, 2025 at 8:52 PM
Fun times when the AI support chatbot hallucinates ACTUALLY placing an order for a replacement item that didn't get delivered.
The actual conversation feels completely effortless until days later when you figure it out because it still hasn't arrived.
The actual conversation feels completely effortless until days later when you figure it out because it still hasn't arrived.
Reposted by Patrick Meenan
Tune in this Wednesday to learn more about the latest WordPress Core Performance Team efforts, including the View Transitions plugin!
✨ SPDY STREAM 005 ✨ A late Friday reveal.
I'm thrilled to welcome @felixarntz.bsky.social next episode. He co-founded the #WordPress Core Performance Team in 2021. and is joining to talk all about it. 🔐 in!
📅 Wednesday July 23RD
🗣️ Felix Arntz
⏰ 1:00pm EST
🔗 bit.ly/spy-stream-005
I'm thrilled to welcome @felixarntz.bsky.social next episode. He co-founded the #WordPress Core Performance Team in 2021. and is joining to talk all about it. 🔐 in!
📅 Wednesday July 23RD
🗣️ Felix Arntz
⏰ 1:00pm EST
🔗 bit.ly/spy-stream-005
July 21, 2025 at 8:12 AM
Tune in this Wednesday to learn more about the latest WordPress Core Performance Team efforts, including the View Transitions plugin!
This is what makes @perfnow.nl so awesome to attend. The hallway track is unbeatable (not just Googlers - Mozilla, Cloudflare, Akamai, Shopify, Speedcurve, etc....).
Attendees opt-in to being listed so you can get a sense for who has registered so far: perfnow.nl/attendees.html
Attendees opt-in to being listed so you can get a sense for who has registered so far: perfnow.nl/attendees.html
July 9, 2025 at 7:44 PM
This is what makes @perfnow.nl so awesome to attend. The hallway track is unbeatable (not just Googlers - Mozilla, Cloudflare, Akamai, Shopify, Speedcurve, etc....).
Attendees opt-in to being listed so you can get a sense for who has registered so far: perfnow.nl/attendees.html
Attendees opt-in to being listed so you can get a sense for who has registered so far: perfnow.nl/attendees.html
Reposted by Patrick Meenan
Firefox shipping scheduler.postTask() and scheduler.yield() for all your long task-avoiding scheduling needs!!
Gecko: Intent to ship: Prioritized Scheduling API
Gecko: Intent to ship: Prioritized Scheduling API
Gecko: Intent to ship: Prioritized Scheduling API
groups.google.com
June 27, 2025 at 5:01 PM
Firefox shipping scheduler.postTask() and scheduler.yield() for all your long task-avoiding scheduling needs!!
Reposted by Patrick Meenan
💣 Working with a retail client recently, we were able to work out that a regression cost them **23% in relative conversions**—a huge loss. The business prioritised an immediate rollback.
Before our project, not only would the regression have gone unnoticed, they’d have no idea its impact.
Before our project, not only would the regression have gone unnoticed, they’d have no idea its impact.
June 25, 2025 at 3:17 PM
💣 Working with a retail client recently, we were able to work out that a regression cost them **23% in relative conversions**—a huge loss. The business prioritised an immediate rollback.
Before our project, not only would the regression have gone unnoticed, they’d have no idea its impact.
Before our project, not only would the regression have gone unnoticed, they’d have no idea its impact.
Reposted by Patrick Meenan
performance.now(), the web performance conference, 30th and 31st of October, Amsterdam. Single track, the best speakers in the industry, plenty of your performance-mad peers around to have fascinating conversations. What's not to like? Let's introduce our speakers ...
perfnow.nl
perfnow.nl
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.
perfnow.nl
June 25, 2025 at 12:35 PM
performance.now(), the web performance conference, 30th and 31st of October, Amsterdam. Single track, the best speakers in the industry, plenty of your performance-mad peers around to have fascinating conversations. What's not to like? Let's introduce our speakers ...
perfnow.nl
perfnow.nl
Reposted by Patrick Meenan
I was excited when @speedcurve.com reached out to me to build their #Shopify app - now it's easier to integrate full real-user performance data collection in Shopify storefronts and correlate that data with bounce rates and conversions.
Now you can see exactly how #webperf impacts your bottom line!
Now you can see exactly how #webperf impacts your bottom line!
SpeedCurve | NEW! SpeedCurve RUM for your Shopify store
Track Core Web Vitals, identify performance issues, measure the impact of site speed on conversion rates, and stay ahead of page slowdowns – all with no coding required.
www.speedcurve.com
June 17, 2025 at 2:26 PM
I was excited when @speedcurve.com reached out to me to build their #Shopify app - now it's easier to integrate full real-user performance data collection in Shopify storefronts and correlate that data with bounce rates and conversions.
Now you can see exactly how #webperf impacts your bottom line!
Now you can see exactly how #webperf impacts your bottom line!
Reposted by Patrick Meenan
what tech companies *haven’t* done layoffs in the last 3 years? it’s time for a goodwill thread
May 20, 2025 at 3:00 PM
what tech companies *haven’t* done layoffs in the last 3 years? it’s time for a goodwill thread
Reposted by Patrick Meenan
Compression Dictionaries are my new favourite thing in #webperf!
Check out this new Case Study about how Google Search uses this new technology, which also explains exactly what this is and how it works using them as an example:
developer.chrome.com/blog/search-...
Check out this new Case Study about how Google Search uses this new technology, which also explains exactly what this is and how it works using them as an example:
developer.chrome.com/blog/search-...
Improving Google Search with Compression Dictionaries | Blog | Chrome for Developers
Learn about how Google Search used Compression Dictionary Transport to boost compression efficiency and improve performance.
developer.chrome.com
May 14, 2025 at 5:01 PM
Compression Dictionaries are my new favourite thing in #webperf!
Check out this new Case Study about how Google Search uses this new technology, which also explains exactly what this is and how it works using them as an example:
developer.chrome.com/blog/search-...
Check out this new Case Study about how Google Search uses this new technology, which also explains exactly what this is and how it works using them as an example:
developer.chrome.com/blog/search-...
Wow, replacing a destroyed iPhone is quite the ordeal.
You can't log in to restore backup since it needs to text a verification code to the phone that isn't set up yet if you don't have another iOS device.
And you can't set up cellular before restoring a backup.
You can't log in to restore backup since it needs to text a verification code to the phone that isn't set up yet if you don't have another iOS device.
And you can't set up cellular before restoring a backup.
May 7, 2025 at 12:15 AM
Wow, replacing a destroyed iPhone is quite the ordeal.
You can't log in to restore backup since it needs to text a verification code to the phone that isn't set up yet if you don't have another iOS device.
And you can't set up cellular before restoring a backup.
You can't log in to restore backup since it needs to text a verification code to the phone that isn't set up yet if you don't have another iOS device.
And you can't set up cellular before restoring a backup.
Reposted by Patrick Meenan
Fascinating deep dive by @iamtk.bsky.social on tracking down an LCP issue:
www.iamtk.co/optimizing-n...
It’s a lot of work for what some might see as a small gain, but uncovered (and fixed!) real issues that might otherwise have gone unnoticed.
www.iamtk.co/optimizing-n...
It’s a lot of work for what some might see as a small gain, but uncovered (and fixed!) real issues that might otherwise have gone unnoticed.
TK's website about software engineering, web development, and career in tech
Learning & Improving with TK: a website about software engineering, web development, and career in tech
www.iamtk.co
May 5, 2025 at 7:17 PM
Fascinating deep dive by @iamtk.bsky.social on tracking down an LCP issue:
www.iamtk.co/optimizing-n...
It’s a lot of work for what some might see as a small gain, but uncovered (and fixed!) real issues that might otherwise have gone unnoticed.
www.iamtk.co/optimizing-n...
It’s a lot of work for what some might see as a small gain, but uncovered (and fixed!) real issues that might otherwise have gone unnoticed.
Is there anyone who DIDN'T see this coming?
This wasn't nation-state and wasn't the cabinet member's history but I'd be surprised if those weren't compromised long ago, just a lot more quietly.
techcrunch.com/2025/05/05/t...
This wasn't nation-state and wasn't the cabinet member's history but I'd be surprised if those weren't compromised long ago, just a lot more quietly.
techcrunch.com/2025/05/05/t...
TeleMessage, a modified Signal clone used by US govt. officials, has been hacked | TechCrunch
Data pertaining to the U.S. Customs and Border Protection, Coinbase, and financial service providers like Scotiabank has reportedly been compromised.
techcrunch.com
May 5, 2025 at 1:35 PM
Is there anyone who DIDN'T see this coming?
This wasn't nation-state and wasn't the cabinet member's history but I'd be surprised if those weren't compromised long ago, just a lot more quietly.
techcrunch.com/2025/05/05/t...
This wasn't nation-state and wasn't the cabinet member's history but I'd be surprised if those weren't compromised long ago, just a lot more quietly.
techcrunch.com/2025/05/05/t...
Reposted by Patrick Meenan
For the compression curious, this is a neat visualization of what gzip does - andrewiggins.github.io/gz-heatmap/?... - via @paul.irish
GZ Heatmap
Examine a heatmap of gzip files to better understand how gzip compresses your code
andrewiggins.github.io
April 22, 2025 at 1:28 PM
For the compression curious, this is a neat visualization of what gzip does - andrewiggins.github.io/gz-heatmap/?... - via @paul.irish
I kind of wonder what the next level of attack surface is going to look like.
Intentionally seeding AI crawler results with a significant amount of "looks right but is malware" kind of attack?
Running random AI models locally not so "safe" in that case either.
Intentionally seeding AI crawler results with a significant amount of "looks right but is malware" kind of attack?
Running random AI models locally not so "safe" in that case either.
1. LLM-generated code tries to run code from online software packages. Which is normal but
2. The packages don’t exist. Which would normally cause an error but
3. Nefarious people have made malware under the package names that LLMs make up most often. So
4. Now the LLM code points to malware.
2. The packages don’t exist. Which would normally cause an error but
3. Nefarious people have made malware under the package names that LLMs make up most often. So
4. Now the LLM code points to malware.
LLMs hallucinating nonexistent software packages with plausible names leads to a new malware vulnerability: "slopsquatting."
April 13, 2025 at 1:13 PM
I kind of wonder what the next level of attack surface is going to look like.
Intentionally seeding AI crawler results with a significant amount of "looks right but is malware" kind of attack?
Running random AI models locally not so "safe" in that case either.
Intentionally seeding AI crawler results with a significant amount of "looks right but is malware" kind of attack?
Running random AI models locally not so "safe" in that case either.
Reposted by Patrick Meenan
For those monitoring Core Web Vitals, we made a small change to the CrUX History API used by CrUX Vis last night and now return 10 months of data, rather than 6 months of data to bring it more inline with the CrUX Dashboard that we're looking to deprecate. Enjoy!
cruxvis.withgoogle.com#/
cruxvis.withgoogle.com#/
CrUX Vis
CrUX Vis is an experiment by the Chrome team to help you explore the Chrome User Experiment Report data with visualizations and helpful links to articles, for a particular web page or origin.
cruxvis.withgoogle.com
April 11, 2025 at 9:36 AM
For those monitoring Core Web Vitals, we made a small change to the CrUX History API used by CrUX Vis last night and now return 10 months of data, rather than 6 months of data to bring it more inline with the CrUX Dashboard that we're looking to deprecate. Enjoy!
cruxvis.withgoogle.com#/
cruxvis.withgoogle.com#/
Reposted by Patrick Meenan
Compression Dictionary Transport: using shared compression dictionaries to reduce the transport size of HTTP responses
@tunetheweb.com @developer.mozilla.org
developer.mozilla.org/en-US/docs/W...
#ECMAScript #JavaScript
@tunetheweb.com @developer.mozilla.org
developer.mozilla.org/en-US/docs/W...
#ECMAScript #JavaScript
Compression Dictionary Transport - HTTP | MDN
Compression Dictionary Transport is a way of using a shared compression dictionary to dramatically reduce the transport size of HTTP responses.
developer.mozilla.org
April 8, 2025 at 12:17 PM
Compression Dictionary Transport: using shared compression dictionaries to reduce the transport size of HTTP responses
@tunetheweb.com @developer.mozilla.org
developer.mozilla.org/en-US/docs/W...
#ECMAScript #JavaScript
@tunetheweb.com @developer.mozilla.org
developer.mozilla.org/en-US/docs/W...
#ECMAScript #JavaScript