Firefox 123 for developers
This article provides information about the changes in Firefox 123 that affect developers. Firefox 123 was released on February 20, 2024.
Changes for web developers
Developer Tools
HTML
- The
<template>
element now supports ashadowrootmode
attribute that allows declarative creation of a shadow DOM subtree. The attribute can be set to eitheropen
orclosed
, which expose or hide JavaScript in the shadow DOM from external code, respectively. These are the same values as themode
option of theattachShadow()
method. (Firefox bug 1870052)
CSS
No notable changes.
JavaScript
- The
Date.parse()
global object has had a number of bug fixes to bring it into line with how other browsers parse the values being passed.- Incorrect day of month (e.g. "31 April") now skips over to the following month (e.g. "1 May"). (Firefox bug 1872333).
- Incomplete time zone (e.g. "1/1/70 gm") or AM/PM (e.g. "1/1/70 10:00 a") are no longer accepted. (Firefox bug 1870570).
- Single number dates are now accepted (e.g.
Date.parse("0")
now returns946684800000
- Sat Jan 01 2000 00:00:00). (Firefox bug 1870434).
SVG
- The
<linearGradient>
and<radialGradient>
SVG elements now support changing the color space to belinearRGB
orsRGB
via thecolor-interpolation
attribute. This can also be applied to the SVG elements via thecolor-interpolation
CSS property.
HTTP
-
The
103 Early Hints
HTTP informational response status code is now enabled for preloading resources that the page is likely to need while the server is still preparing the full response. This can significantly reduce page load time. Note that support for using the103 Early Hints
header for preconnecting was added in Firefox 120. For more details see Firefox bug 1874445.
APIs
-
The Web Authentication API now supports cross-origin credential creation.
Specifically
navigator.credentials.create({publicKey})
can now be called in nested browsing contexts loaded from a different origin to the top-most document, if allowed by aFeature-Policy: publickey-credentials-create
on the top level nesting<iframe>
. (Firefox bug 1870863).
DOM
-
Custom locale support for the IndexedDB API has been deprecated, including the
options.locale
parameter toIDBObjectStore.createIndex()
, and theIDBIndex
propertiesisAutoLocale
andlocale
. (Firefox bug 1872675 and Firefox bug 1730706).
Media, WebRTC, and Web Audio
Removals
The IDBLocaleAwareKeyRange
interface has been removed (Firefox bug 1730706).
WebDriver conformance (WebDriver BiDi, Marionette)
WebDriver BiDi
- Added the network.fetchError event that is emitted when a network request ends in an error (Firefox bug 1790375).
- Support for the browsingContext.locateNodes command has been introduced to find elements on the given page. Supported locators for now are
CssLocator
(Firefox bug 1855023) andXPathLocator
(Firefox bug 1869536). - Improved the browsingContext.create command on Android to seamlessly switch to opening a new tab if the
type
argument is specified aswindow
(Firefox bug 1875086). - Fixed an issue with the deserialization process of a
DateRemoteValue
, where the presence of a non-standard (ISO 8601) date string such as200009
did not trigger an error (Firefox bug 1872116). - Fixed an issue with the script.evaluate, script.callFunction, and script.disown commands where specifying both the
context
andrealm
arguments would result in aninvalid argument
error, rather than simply ignoring therealm
argument as intended (Firefox bug 1873688).
Marionette
- Fixed a bug with Element Send Keys where sending text containing surrogate pairs would fail (Firefox bug 1866431).
Changes for add-on developers
- Addition of the
contextualIdentities.move
function enables items to be moved in the list of contextual identities. This function enables extensions to customize the order in which contextual identities display in the UI (Firefox bug 1333395).
Experimental web features
These features are newly shipped in Firefox 123 but are disabled by default. To experiment with them, search for the appropriate preference on the about:config
page and set it to true
. You can find more such features on the Experimental features page.
-
Web Codecs API:
dom.media.webcodecs.enabled
.The video interfaces of the Web Codecs API are supported on Linux desktop on Nightly. These include:
VideoEncoder
,VideoDecoder
,EncodedVideoChunk
,VideoFrame
,VideoColorSpace
. (Firefox bug 1874445).
Older versions
- Firefox 122 for developers
- Firefox 121 for developers
- Firefox 120 for developers
- Firefox 119 for developers
- Firefox 118 for developers
- Firefox 117 for developers
- Firefox 116 for developers
- Firefox 115 for developers
- Firefox 114 for developers
- Firefox 113 for developers
- Firefox 112 for developers
- Firefox 111 for developers
- Firefox 110 for developers
- Firefox 109 for developers
- Firefox 108 for developers
- Firefox 107 for developers
- Firefox 106 for developers
- Firefox 105 for developers
- Firefox 104 for developers
- Firefox 103 for developers
- Firefox 102 for developers
- Firefox 101 for developers
- Firefox 100 for developers
- Firefox 99 for developers
- Firefox 98 for developers
- Firefox 97 for developers
- Firefox 96 for developers
- Firefox 95 for developers
- Firefox 94 for developers
- Firefox 93 for developers
- Firefox 92 for developers