Yoav Weiss

That sucks!! :(

*web frameworks klaxon*

If you work on a web framework then there is a w3c proposed community group: the Web Frameworks Community Group, a place for framework folk to feedback to browser vendors about what they want to see!

If you want this it needs your support!

www.w3.org/community/gr...

Congrats Brian!!

Compression Dictionaries: How Google & Shopify Are Bringing SPA Speed to MPA Websites YouTube video by Lessons of a CTO

After implementing Compression Dictionaries back in December, I sat down with @yoav.ws and @patmeenan.com to discuss getting the most out of them and provide some visuals for those new to the concept. Check out the video below:

youtu.be/YR2er3EiYnM / lessonsofacto.com/videos/032-c...

Sounds interesting! I can take a look once I'm back (currently on a mountain..)

Something I've been helping @yoav.ws with. A proposal to allow you to measure Speculation Rules API and <link rel=preload> usage.

Are you over-speculating? Under-speculating?

Until now you've only really been able to measure secondary impact, but with this proposal you'll can have better data.

How to load CSS (fast). 13th Dec 2025 by Yoav Weiss.

Speeding up CSS with compression dictionaries. @yoav.ws shows how combining critical and full CSS via compression dictionaries cuts bandwidth and accelerates page transitions. Works now in Chromium. #performance #css

calendar.perfplanet.com/2025/how-to-...

shout out to @frehner.me for adding name only container queries in Safari!

bugs.webkit.org/show_bug.cgi...

How to load CSS (fast) Loading styles on the web is something that looks trivial at first. You just add a <link rel=stylesheet> to your page (or <style> for inline styles) and you're done. But if you wanted to load CSS fas...

Web Performance Calendar day 13 with Yoav Weiss (@yoav.ws) showing us a clever and creative way to ship *only* critical/necessary CSS for each page type (home, search, etc) while also avoiding duplicate code in the CSS bundles.

calendar.perfplanet.com/2025/how-to-...

Decoding shouldn't be slower though, right? It's just replacing Huffman with arithmetic, isn't it?

We have Custom Elements, but do we also need Custom Attributes?

This was discussed at TPAC. Is it something you'd like on the platform?

https://github.com/WICG/webcomponents/issues/1029

Out-of-order HTML patching, another proposal from TPAC, lets HTML be presented non-linearly, and a single file can update multiple parts of the page.

Would this feature be useful to you?

Thanks for coming over and for doing the work! Having developers in the room during those discussions is sooooo important

Last time I looked, github.com/tc39/proposa... was an interesting primitive on that front. I don't think it'd eliminate the need for bundlers, but would enable better bundler output

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

GitHub - blittle/iframe-data-attributes: Iframe Data Initialization Attributes Iframe Data Initialization Attributes. Contribute to blittle/iframe-data-attributes development by creating an account on GitHub.

I'm proposing a change to iframes that will allow child frames synchronous access to data attributes on the parent frame. Let me know your thoughts: github.com/blittle/ifra...

✨ SPDY STREAM 011 ✨ w/ @krzksz.bsky.social & @yoav.ws
After deploying the SPECULATION RULES API to their merchants, they join me this week to discuss the experience and their findings. Join us! (updated day and time)
📆 Thursday Sept 25
⏰ 11am EST, 5pm CEST
🔗 bit.ly/spdy-stream-011

Any chance you'd be interested to hop over to a WG call at some point to discuss this? (or maybe TPAC)

WIP: Add a mechanism to fetch to track progress by lukewarlow · Pull Request #1843 · whatwg/fetch This is not ready for review this is WIP. At least two implementers are interested (and none opposed): … … Tests are written and can be reviewed and commented upon at: … Implementation b...

@lukewarlow.dev I just discovered github.com/whatwg/fetch... thanks to @jakearchibald.com
Something like this has been a recurring request at the WebPerfWG, beyond `fetch()` github.com/w3c/resource...

It'd be great if this could cover both!

Fetch streams are great, but not for measuring upload/downloading progress They're inaccurate, and there are better ways.

📝 Fetch streams are great, but contrary to popular belief, they're not good for measuring upload/downloading progress.

⬇️ Here's why, and how to avoid the gotchas ⬇️

jakearchibald.com/2025/fetch-s...

Yaaaaaaaaaaay!!

Hey! I think Ben Sehl or Max Stoiber may be a better fit for a Liquid chat

x.com/mxstbr x.com/benjaminsehl

Speculation Rules at Shopify We all love quick and snappy online shopping experiences. Fast navigations from one product page to the next reduce friction and allow people to find all the products they want in that store. To achie...

Great post and it's been a pleasure helping @krzksz.bsky.social and @yoav.ws get this working on Shopify.

performance.shopify.com/blogs/blog/s...

I also agree this makes sense..

Dude, just climb all the hills instead of looking at them and you'll be good

Congrats!!

Me, sitting behind a cuddly toy of a fox. Ok it's obviously Firefox.

Starting my new role on Monday. Could be anywhere.

portrait of Jason in Portland

today is my 40th birthday. to toot my own horn a bit, I'm the happiest, healthiest, and most successful I've ever been, so I'm going to indulge myself and do one of those "40 things that made me who I am" threads

so buckle up (or mute me for the next little bit 😆)

Blink: Intent to Implement and Ship: Http cookie prefix

Animating zooming using CSS: transform order is important… sometimes How to get the right transform animation.

CSS uses a complex algorithm to decide how to animate transforms. If you get it wrong, as many folks do, you end up with an unnatural animation.

Here's how it works, and how to avoid the pitfalls.

jakearchibald.com/2025/animati...