Firefox 92 for developers
This article provides information about the changes in Firefox 92 that will affect developers. Firefox 92 was released on September 7, 2021.
Note: See also Time for a review of Firefox 92 on Mozilla Hacks.
Changes for web developers
HTML
No changes
CSS
- The keywords
avoid-page
andavoid-column
are now supported for thebreak-inside
property (Firefox bug 1722945). - The two-value syntax for the
font-size-adjust
property is now supported (Firefox bug 1720131). - The
size-adjust
descriptor is now supported (Firefox bug 1720131). - The CSS
accent-color
property has been implemented (Firefox bug 1722031). - The
system-ui
value is now supported for thefont-family
property (Firefox bug 1226042).
JavaScript
Object.hasOwn()
can be used to test whether a property was defined on an object or inherited (Firefox bug 1721149).- The default 5MB storage quota is now available to each origin. The quota previously applied to an entire domain group (also known as eTLD+1 domain; e.g.,
*.wikipedia.org
). (Firefox bug 1064466). - Storage quotas for
Window.localStorage
are now shared with IndexedDB API andCache
(Firefox bug 742822).
HTTP
- Firefox will automatically upgrade an HTTP request to HTTPS when a usable HTTPS RR is available.
It will also use information provided in an HTTPS RR to optimize the process of establishing HTTPS connections—this is conceptually similar to using the
Alt-Svc
header. (Firefox bug 1721132).
APIs
- The
disabledFeatures
static property has been implemented for Custom Elements (Firefox bug 1723396).
DOM
- The Imperative Slotting API (part of the Shadow DOM API) Has been implemented. (Firefox bug 1705141)
- You can now monitor for changes to text selections in
<input>
or<textarea>
by listening forselectionchange
events inHTMLInputElement
andHTMLTextAreaElement
, respectively (Firefox bug 1648944).
Media, WebRTC, and Web Audio
- Access to audio output devices, like speakers and headphones, is now protected by the speaker-selection feature policy (Firefox bug 1577199).
WebDriver conformance (Marionette)
- Improved support for the
webSocketUrl
capability, which now returns the WebDriver BiDi websocket URL iftrue
was passed and if BiDi is supported. (Firefox bug 1692984).
Changes for add-on developers
- Support for
cookieStoreId
is added todownloads.download
,downloads.DownloadQuery
, anddownloads.DownloadItem
. The addition to the typesdownloads.DownloadQuery
anddownloads.DownloadItem
provides support indownloads.search
anddownloads.erase
. Web extensions can now associate downloads with specific cookie stores, such as container tabs (contextual identities). (Firefox bug 1669566)
Older versions
- Firefox 91 for developers
- Firefox 90 for developers
- Firefox 89 for developers
- Firefox 88 for developers
- Firefox 87 for developers
- Firefox 86 for developers
- Firefox 85 for developers
- Firefox 84 for developers
- Firefox 83 for developers
- Firefox 82 for developers
- Firefox 81 for developers
- Firefox 80 for developers
- Firefox 79 for developers
- Firefox 78 for developers
- Firefox 77 for developers
- Firefox 76 for developers
- Firefox 75 for developers
- Firefox 74 for developers
- Firefox 73 for developers
- Firefox 72 for developers
- Firefox 71 for developers
- Firefox 70 for developers
- Firefox 69 for developers
- Firefox 68 for developers
- Firefox 67 for developers
- Firefox 66 for developers
- Firefox 65 for developers
- Firefox 64 for developers
- Firefox 63 for developers
- Firefox 62 for developers
- Firefox 61 for developers