Cropped screenshot of the HTML specification. Relevant visible content reads: The srcset and sizes attributes can be used, using the w descriptor, to provide multiple images that only vary in their size (the smaller image is a scaled-down version of the bigger image). In this example, a banner image takes up the entire viewport width (using appropriate CSS). <h1><img sizes="100vw" srcset="wolf-400.jpg 400w, wolf-800.jpg 800w, wolf-1600.jpg 1600w" src="wolf-400.jpg" alt="The rad wolf"></h1>

I had no idea that the subject of the RICG’s canonical responsive images examples endured in the specification to this very day:

Responsive Images Done Right: A Guide To And srcset — Smashing Magazine A few days ago, we published an [article on Picturefill 2.0](https://www.smashingmagazine.com/2014/05/12/picturefill-2-0-responsive-images-and-the-perfect-polyfill/), a perfect polyfill for responsive images. Today’s article complements Tim Wright’s article and explains exactly how we can use the upcoming `` element and srcset, with simple fallbacks for legacy browsers. There is no reason to wait for responsive images; we can actually have them very soon.

I think it either existed in the spec already or I copied it from somewhere.

@ericportis.com did you come up with it? www.smashingmagazine.com/2014/05/resp...

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.

> WHATWG, who took over responsibilities from the W3C in 2019.

Arguably in 2004. :) html.spec.whatwg.org/multipage/in...

Congrats & nice work! :)

Can it run DOOM?

It's time for Interop 2026! This is a cross-browser effort where we agree on a set of focus areas to improve compatibility.

Here's how things went in 2025, and what we're taking on for 2026: hacks.mozilla.org/2026/02/laun...

Does the XSLT implementation support `disable-output-escaping="yes"`?

Or using HTML syntax at the edges (parse and serialize) but XML tools in the middle

Is anybody still using xml/HTML polyglots for anything moder (Syntax that is valid in both html and xml)
Wondering whether those are something that needs to be considered for future HTML enhancement or a thing of the past...

Testing with software.hixie.ch/utilities/js... canShare returns false but text and url actually work on Android. So... shipping on Android at least, but there are bugs.

Jake's survey is closed.

Maybe it's not the fastness that lowers the conversion rate, but something else, like maybe the fastest websites are more likely to have not-so-great design?

Accept cookies! Subscribe to our newsletter for 15% off! Hey, do you want to take a survey of how much you like our website?

We mentioned on Winging It that we might show some of our favorite browser tips. Here's one of many that I find delightful.

If you are working with shape-outside, then Firefox has a great path editor. I made a quick video to show how it works.

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Interop 2026 is now open for proposals!

This is your chance to tell browser-makers which well-defined, well-tested features you wish had better support across browsers.

⬇️ Here's how ⬇️
github.com/web-platform...

Gecko: Intent to Ship: CSS View Transitions L1

Not saying you should but it should work

Or <script xmlns="http://www.w3.org/1999/xhtml" src="..."/>! If there's at least one element in a known namespace, browsers switch away from the XML tree view.

Right, though ARIA attributes are superglobal.

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

Did you know?

You can style XML with CSS using
<?xml-stylesheet href="style.css"?>

Yay! It's the first Firefox release since I've joined the team, so let's take a look at some of the new developer-facing features in Firefox 142… 🧵

In your demo, the relevant element is a flex item, which is not inline.

Here's a demo showing that actual inline doesn't work: software.hixie.ch/utilities/js...

The part about display: inline is wrong.

This:

> establishes an inline formatting context and thus contains only inline-level boxes.

Refers to what the element contains. A block box establishes an inline formatting context when it has no block-level children. The element itself is still a block.

Sure. People used to call it XHTML. :) If there's an element in a known namespace browsers will apply the UA stylesheet. If you add a script element it will run (if scripting is enabled).

I don't know if feed readers will get confused though.