Firefox 109 for developers

• The range element supports the list attribute, which links via an id to a <datalist> to allow Firefox to display tick marks along the range.

• The <system-color> CSS data type now supports the values Mark, MarkText, and ButtonBorder (bug 1638052).
• The content-visibility CSS property now supports the value auto, which allows content to skip rendering if it is not relevant to the user (bug 1791759).

No notable changes.

Removals

• SVGGraphicsElement.getTransformToElement() has been removed. This follows its removal from the SVG2 specification in 2015, and from other major browsers. (bug 1803790).
• The SVGGraphicsElement.nearestViewportElement and SVGGraphicsElement.farthestViewportElement attributes have been disabled by default in nightly and early beta builds (behind preference svg.nearestAndFarthestViewportElement.enabled). SVGElement.viewportElement can be used as an alternative to SVGGraphicsElement.nearestViewportElement. They have been removed from the SVG2 specification and are likely to be removed entirely from Firefox in a future release. (bug 1133174).

• The 'unsafe-hashes' value for Content-Security-Policy source directives is now supported. For more information, see CSP unsafe-hashes (bug 1343950).

• The scrollend events are now supported, which indicate that the user has completed scrolling in Element and Document objects. For more information, see Element: scrollend event and Document: scrollend event (bug 1797013, bug 1803435).

WebDriver BiDi

• The connection details for WebDriver BiDi are now written to WebDriverBiDiServer.json instead of WebDriverBiDiActivePort, which contains both the port (ws_port) and the host (ws_host). This file is located in the Firefox profile folder (bug 1792875).
• Added support for subscribing / unsubscribing to individual contexts when using session.subscribe and session.unsubscribe (bug 1723102).
• Added support for serializing Node objects (bug 1770731).
• Fixed the columnNumber for exceptions and stackTraces to be 0-based (bug 1796073).

Marionette

• Fixed a bug where WebDriver:NewWindow and WebDriver:SwitchToWindow were not focusing the new window properly (bug 1798655).
• Fixed a bug where WebDriver:FindElement (and similar commands) would fail if the Firefox window was occluded by other applications on Windows (bug 1802473).

• Manifest V3 is now supported with the ability to sign and release Manifest V3 extensions on AMO. See the Manifest v3 signing available November 21 on Firefox Nightly blog post for more information.
• The default Content Security Policy (CSP) for Manifest V3 extensions has been updated to include upgrade-insecure-requests. This means that, by default, all network requests are upgraded to use https:. Extensions that need to use http: can do so by overriding the default CSP using the content_security_policy manifest.json key (bug 1797086).
• The property secretKeyLength has been added to webRequest.SecurityInfo. This property provides the length in bits of the secret key in the security properties of a web request (bug 1778473).