Firefox 100 for developers

This article provides information about the changes in Firefox 100 that will affect developers. Firefox 100 was released on May 3, 2022.

Changes for web developers

HTML

No notable changes.

CSS

  • CSS media features for dynamic-range and video-dynamic-range are now supported. You can now test whether a user agent or an output device supports the combination of brightness, contrast ratio, and color depth by using dynamic-range and in the video plane by using video-dynamic-range (bug 1751217).

JavaScript

No notable changes.

HTTP

Removals

APIs

DOM

WebAssembly

  • WebAssembly now supports exceptions that can be thrown and caught in either WebAssembly or Javascript (or some other runtime), crossing between the environment boundaries if not handled. The JavaScript representations of WebAssembly exceptions are WebAssembly.Exception and WebAssembly.Tag (bug 1759217).

WebDriver conformance (Marionette)

  • Added support for user prompts (e.g. alert) on Android (bug 1708105).

Older versions