Firefox 105 for developers

This article provides information about the changes in Firefox 105 that affect developers. Firefox 105 was released on September 20, 2022.

Changes for web developers


No notable changes.


  • Embedded content, such as SVG definitions and content in an <iframe>, now respects the theme preferences of the elements in which it is embedded, rather than OS or browser preferences (which may be different). Specifically, embedded content now inherits the color-scheme of the embedding element, and prefers-color-scheme media queries in the embedded content respect this value rather than the OS/browser level theme setting (Firefox bug 1779457).




WebDriver conformance (WebDriver BiDi, Marionette)

WebDriver BiDi

  • On systems with IPv6 preferred DNS resolution clients will no longer fail to connect when localhost is used as host for the WebSocket server (Firefox bug 1769994).
  • Improved RemoteValue support to allow plain JS objects with simple JSON-serializable fields to be serialized (Firefox bug 1779226).


  • The WebDriver:GetElementProperty command is now able to return node properties as set by web content (Firefox bug 1398792).

Changes for add-on developers

Older versions