Firefox 153 just landed, and comes with web platform features like:
🎉 popover="hint"
🎉 Picture-in-picture
🎉 IDB getAllRecords()
🎉 JS Promise Integration for wasm
🎉 JS import-as-text
…And more! https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/153
@firefoxwebdevs Is the `at-supports selector(::-webkit-scrollbar)` only for the top level selector, or do all `::-webkit-scrollbar-*` pseudos return true? (MDN compat table says no but just want to check)
I'm sure there was a debate about this, but when I call an at-support rule I expect it to reflect reality, which this does not, and that seems like a bad precedent. (`:visited` in JS not withstanding)
PS: I know I know, don't mess with scrollbars… but sometimes I need to mess with scrollbars.
@chriskirknielsen It's just for the main selector, although we avoid throwing errors on parsing the others with JS. Unfortunately we had to do this for compat. Here's some of the ugly details https://bugzilla.mozilla.org/show_bug.cgi?id=1977511
As for messing with scrollbars, we support the web standard ways https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Scrollbars_styling
@firefoxwebdevs Hate to see it, but glad to see there's an escape hatch at least!
The standard way is what I prefer, definitely! Though sometimes I'm given a design where I really have to mess with scrollbars like making them extra large (scrollbar-width: large, I yearn for thee) or inset into the element (crossing my fingers for `scrollbar-offset` to get implemented) so I cannot go the standard way, as much as I want to. 🫠
Jul 21, 2026, 12:46 PM@firefoxwebdevs
Nice. But:
Why did you get back to the führer-page though?
@micha I guess they're wanting to reach more people (I don't run that account). But the good news is @FirefoxOfficial 😀
“Adds the publicSuffix API, enabling extensions to determine the (...) public suffix of a hostname using the browser's built-in Public Suffix List.”
Oh nifty, that means I've got an extension I'll want to do a version upgrade for.
@julian there's also a web standard API related to this, but we don't support it yet https://html.spec.whatwg.org/multipage/browsers.html#dom-origin-issamesite
@firefoxwebdevs Popover hint is nice for future projects.
Tree functions are going to simplify my css which is always great, but I still want a `children-count()` to get rid of my subgrid span 1000 rows/columns hacks. Tree functions, plus `children-count()` plus `attr()` would be so good I'd get butterflies in my stomach.
I'm excited to see the shenanigans that devs come up with while using/exploiting jpeg-xl's features...
@firefoxwebdevs ...especially with progressive decode and storing extra data in its extra channels.
Maybe using them for bump mapping and specular highlight channels, or some crazy asset packing.
At least without the extra network requests, or trying to figure out the preloads and getting told by web-hosts that they don't support http3.
@spartanatreyu how would this packing of this additional data differ to, say, a zip file?
@firefoxwebdevs I'd imagine that with either zip archive or jpeg-xl shenanigan methods, once you're able to access/extract the information then there's no real difference once everything's loaded.
But with the jpeg-xl method, you could put it in an img tag and see a default image.