Firefox 113 release notes for developers

Changes for web developers

HTML

No notable changes.

CSS

• The color(), lab(), lch(), oklab(), oklch(), and color-mix() functional notations are now supported, along with the forced-color-adjust property. For more information on the functional notations, see the CSS color value documentation. (Firefox bug 1352753, Firefox bug 1813497, Firefox bug 1818819, Firefox bug 1824526).
• The :nth-child of <selector> syntax allows you to target a group of children based upon the An+B rule that also matches a defined selector. See (Firefox bug 1808229) for more details.
• The scripting media feature is now supported. See (Firefox bug 1166581) for more details.
• The content property now supports all image type including, <gradient>, image-set() and url(). See (Firefox bug 1684958) for more details. There is currently an issue with the ::before and ::after pseudo selectors that means that they don't paint <gradient>s. See (Firefox bug 1832901) for more details.

JavaScript

No notable changes.

APIs

• CanvasRenderingContext2D.reset() and OffscreenCanvasRenderingContext2D.reset() are now supported, and can be used to return the associated rendering context to its default state. (Firefox bug 1709347).
• The Compression Streams API is now supported. The interfaces provided by this API are used to compress and decompress data using the gzip and deflate formats (Firefox bug 1823619).
• The deprecated and non-standard mozImageSmoothingEnabled property is now disabled. See the imageSmoothingEnabled property for smoothing in scaled images (Firefox bug 1822955).

Media, WebRTC, and Web Audio

• The AV1 video codec is now enabled on Android. Hardware accelerated decoding is used if supported by the device (Firefox bug 1672276).
• The following WebRTC methods, properties, and dictionaries are now supported: RTCRtpSender.getCapabilities(), RTCRtpReceiver.getCapabilities(), RTCRtpSender.setStreams(), RTCSctpTransport & RTCPeerConnection.sctp, RTCVideoSourceStats & RTCAudioSourceStats, RTCPeerConnection.connectionState, and RTCPeerConnectionStats. The corresponding bug reports are, respectively: Firefox bug 1531460, Firefox bug 1531461, Firefox bug 1510802, Firefox bug 1278299, Firefox bug 1804678, Firefox bug 1265827, and Firefox bug 1531087.

Removals

• The deprecated and non-standard CanvasRenderingContext2D.mozTextStyle attribute was permanently removed. This was previously hidden behind a preference. (Firefox bug 1294362).
• The deprecated and non-standard attributes mozRTCPeerConnection, mozRTCIceCandidate, and mozRTCSessionDescription were permanently removed (Firefox bug 1531812).

WebDriver conformance (WebDriver BiDi, Marionette)

WebDriver BiDi

• Added support for serializing Node objects within a Shadow DOM and the shadowRoot property on Node objects (Firefox bug 1802137).
• Added support for cached responses for the network.responseStarted and network.responseCompleted events (Firefox bug 1806802 and Firefox bug 1806794).
• Fixed an issue where the browsingContext.domContentLoaded and browsingContext.load events were missing for navigations using document.open() and document.close() (Firefox bug 1822772).
• Fixed an issue where the script.callFunction command was throwing an invalid argument error if an unknown object was passed as an argument, instead of the expected no such handle error (Firefox bug 1821039).

Marionette

• The moz:useNonSpecCompliantPointerOrigin capability is now deprecated and will be fully removed in Firefox 116 (Firefox bug 1824911).
• Implemented the WebDriver:FindElementFromShadowRoot and WebDriver:FindElementsFromShadowRoot commands (Firefox bug 1700095).
• Implemented the WebDriver:GetComputedLabel and WebDriver:GetComputedRole commands (Firefox bug 1585622).
• Added support for the background parameter of the WebDriver:Print command (Firefox bug 1783086).
• Added support for the orientation parameter of the WebDriver:Print command (Firefox bug 1791819).
• Fixed an issue with DOMTokenList instances, which are now returned as collections instead of arbitrary objects (Firefox bug 1823464).

Changes for add-on developers

• When an extension registers multiple listeners for the same event, all the event listeners are called when the event page wakes up, instead of only the first one (Firefox bug 1798655).
• Support is now provided for the declarativeNetRequest API (Firefox bug 1782685).
• The gecko_android sub-key has been added to the browser_specific_settings key. This sub-key enables an extension to specify the range of Firefox for Android versions it is compatible with (Firefox bug 1824237).

Other

• Support for animated AVIF (AV1 Image Format files) images. Previously, they would display as still images with no way for web pages to detect this and fall back to another format. (Firefox bug 1825580).