Firefox for Web Developers

RE: @keithamus@indieweb.social

Sorry everyone. You're about to spend a ton of time on this.

My score is 0.0028 💅 (although I get different scores on different screens - my best is on my MacBook)

JavaScript Iterator․zip landed in Firefox 148, making it simple to loop over multiple things at the same time. Here's how it works:

CSS shape() landed in Firefox 148. It's similar to path(), but allows the full expressiveness of CSS…

WebAssembly is a second-class language on the web, but how can we make it first-class? WebAssembly Components could be the answer…

https://hacks.mozilla.org/2026/02/making-webassembly-a-first-class-language-on-the-web/

You can throw away innerHTML and replace it with the new setHTML(), which has a built-in sanitizer. Here's how it works:

The Sanitizer API landed in Firefox 148, along with element.setHTML().

This lets you fully configure how HTML strings are cleaned as they're parsed.

https://hacks.mozilla.org/2026/02/goodbye-innerhtml-hello-sethtml-stronger-xss-protection-in-firefox-148/

Firefox 148 is out now, and adds some great web platform features:

🎉 The HTML Sanitizer API
🎉 CSS shape()
🎉 Trusted Types
🎉 Nav API's addHandler
🎉 Iterator zip & zipKeyed
🎉 ancestorOrigins

And more!

https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/148

HTML might be getting a new type of tag, which… hasn't happened this millennium. Here's the new syntax, and how it works.

And here's the explainer on HTML patching https://github.com/WICG/declarative-partial-updates/blob/main/patching-explainer.md

If you had to pick _one_, which web platform feature would you like in Firefox that isn't part of the Interop 2026 effort? https://hacks.mozilla.org/2026/02/launching-interop-2026/#new-features

Here's a quick rundown of what we delivered as part of Interop 2025, and what's planned for Interop 2026!

More details on the features and focus areas: https://hacks.mozilla.org/2026/02/launching-interop-2026/

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: https://hacks.mozilla.org/2026/02/launching-interop-2026/

AI Controls (formerly 'kill switch') are landing in today's Firefox Nightly, and will land with Firefox 148 later this month.

For the full details, see the Firefox blog https://blog.mozilla.org/en/firefox/ai-controls/