Firefox 111 for developers

This article provides information about the changes in Firefox 111 that affect developers. Firefox 111 was released on March 14, 2023.

Changes for web developers



  • CSS color functions color(), lab(), lch(), oklab(), and oklch() are now supported. These features are disabled by default and can be enabled by setting the preference layout.css.more_color_4.enabled to true. For more information, see the CSS color value documentation (Firefox bug 1352757 and Firefox bug 1128204).


No notable changes.


  • The context-stroke and context-fill values are now supported inside <marker> elements. For more information on using these values with fill and stroke properties, see the <marker> documentation (Firefox bug 752638).




  • The FormData constructor now accepts a second optional submitter parameter to specify a submit button. If the button has a name or is an image button, it will contribute to the form data set. This makes it possible to create a FormData object with the same data set as a vanilla form submission triggered by the button. See Firefox bug 1812696 for more details.

Media, WebRTC, and Web Audio

WebDriver conformance (WebDriver BiDi, Marionette)

WebDriver BiDi

  • Changed the behaviors for handling stale elements checks based on recently updated WebDriver classic specification. See Firefox bug 1808894 for more details.


  • Fixed an issue where returning a ShadowRoot from WebDriver:ExecuteScript causes a cyclic object value error. See Firefox bug 1764594 for more details.

Changes for add-on developers

  • matchDiacritics has been added to the Find.find API. This option enables searches to distinguish between accented letters and their base letters. For example, when set to true, searching for "résumé" does not find a match for "resume" Firefox bug 1680606.
  • search.query has been added, providing search API compatibility with Chromium-based browsers Firefox bug 1804357.
  • The disposition property has been added to, enabling results to be displayed in a new tab or window Firefox bug 1811274.

Older versions