JSON... probably a mistake
Ajaxing HTML slags in 2009... measurably better

Just a guy sitting a little farther from the wifi router, waiting literal minutes for the interactive section of the fancy project management app's otherwise-static pages to <React> a list of 10 links to tickets.

amazing. thanks for sharing

Thank you Stefan! Fixed.

A screenshot of the engineering blog homepage with links to two posts about this feature, linked in the post

If you missed it last week, parts 1 and 2 of my latest Squarespace Engineering Blog series are now out. Learn about the upcoming HTML video & audio loading=lazy feature and how it came to be standardized.

1: engineering.squarespace.com/blog/2026/sq...
2: engineering.squarespace.com/blog/2026/ho...

Web Weekly 189 — Topics: Not existing font-family fallbacks, HTML in canvas elements, Number formatting with Intl, Name-only @container queries, loading="lazy" for videos, sizes="auto" for images.

Web Weekly 189 just went out! 🥂

This one covers `sizes="auto"` for responsive images, lazy loading videos, HTML in canvas, name-only container queries, and why your `font-family` fallbacks might not work the way you think.

Read it online: https://webweekly.email/

you can’t triple stamp a double stamp

Highly recommended!!

Oh thanks! I try to frame technical talks/courses with broader priorities and appreciate that you noticed, Sam

Haven’t tried it out yet but I like how it looks!

...and if you missed part 1: bsky.app/profile/scot...

How To Use Standard HTML Video & Audio Lazy-Loading on the Web Today — Squarespace Engineering Blog HTML video and audio lazy loading is now a web standard and quickly gaining support in all major browsers. Given Squarespace’s role in proposing and implementing it, we’re very excited to see how deve...

How To Use Standard HTML Video & Audio Lazy-Loading on the Web Today. Part 2 of my Squarespace Engineering blog series on the topic. Please enjoy!

Chrome's release roadmap now has this feature listed as enabled by default in Chrome 148 (without a preference flag), slated to auto-update May 5 🥳

🎨 I gotta say, my latest is a little treasure trove: what even is `contain`?! csswizardry.com/2026/04/what...

Dang. great resource.

“How We Helped Bring HTML Video & Audio Lazy Loading to Today’s Browsers” next to HTML Living Standard page dated 23 March 2026 with the loading attribute spec.

Squarespace and web standards: how we helped bring HTML video and audio lazy loading to today’s browsers. Scott Jehl describes how the team proposed loading="lazy" for video and audio, making it an official web standard. #html #performance

engineering.squaresp...

I recall some very helpful nudges! 👍

sorry, was waiting for it to load. Looks perfect!

center that div vertically

Hello

Thanks @keithamus.social for the reminder today that any sufficiently long css property name is indistinguishable from standard 😅

The gradient fill!

lookin' real sharp, Mat.

Thanks Brian! Appreciated your help during the standardization process too

HTML Video: Allow a child IMG (with an optional Picture Element wrapper) to Control the Video Poster Image · Issue #10378 · whatwg/html What is the issue with the HTML Standard? The video element currently offers a single poster attribute, which allows us to load one poster image source. This is limiting when attempting to deliver ...

👀 wouldn't mind seeing this one next github.com/whatwg/html/...

Thx friend!

Excited this went out!
If you’re interested in usage tips before part 2 comes out next week, the @developer.mozilla.org docs are updated (thx to @tunetheweb.com )

True

You were the first to dive in on writing the platform tests for us. No small part! Cheers

Squarespace & Web Standards: How We Helped Bring HTML Video & Audio Lazy Loading to Today’s Browsers — Squarespace Engineering Blog At Squarespace, many of our core products are built on web standards, and our engineers are constantly pushing the boundaries of the web’s capabilities. Occasionally, those boundaries reveal a limitat...

New on the Squarespace Engineering Blog! Squarespace & Web Standards: How We Helped Bring HTML Video & Audio Lazy-Loading to Today’s Browsers.

I'm real proud of the teamwork that went into this. Stay tuned for part 2 next week, which will cover dev best practices for using this new HTML standard.