Firefox 85 for developers
This article provides information about the changes in Firefox 85 that will affect developers. Firefox 85 was released on January 26, 2021.
Note: See also January brings us Firefox 85 on Mozilla Hacks.
Changes for web developers
Developer Tools
- Developers can now use the Page Inspector to toggle the
:focus-visible
pseudo-class for the currently selected element (in addition to the pseudo classes that were previously supported::hover
,:active
and:focus
,:focus-within
, and:visited
). (Firefox bug 1617608).
HTML
<link rel="preload">
is now enabled. (Firefox bug 1626997).
Removals
- The
<menuitem>
HTML element is no longer available — it has been hidden behind thedom.menuitem.enabled flag
. (Firefox bug 1680596).
CSS
- The
:focus-visible
pseudo-class is now enabled. (Firefox bug 1445482). - The
pinch-zoom
value for thetouch-action
property is now enabled. (Firefox bug 1329241).
JavaScript
-
The
collation
property can now be specified in the options passed to theIntl.Collator()
constructor (Firefox bug 1670062). This allows developers to write code with greater clarity:js// Old method let pinyin = new Intl.Collator(["zh-u-co-pinyin"]); // New method let pinyin = new Intl.Collator("zh", { collation: "pinyin" });
Plugins
- Flash support has been completely removed from Firefox (Firefox bug 1675349).
APIs
No changes.
WebDriver conformance (Marionette)
- Fixed a potential page load timeout situation when
WebDriver:ElementClick
is called for a link with atarget
other than_blank
(Firefox bug 1678455). - Using web element references on browsing contexts other than the originating one now correctly returns a
no such element
error instead of astale element reference
error (Firefox bug 1684827).
Known bugs
- WebDriver commands following a call to
WebDriver:SwitchToFrame
can fail with a "no such window" error if the frame's content hasn't yet finished loading (Firefox bug 1691348). - After a cross-group page navigation, accessing a previously-retrieved element might not always raise a "stale element" error, and can also lead to a "no such element" error. To prevent this, set the
marionette.actors.enabled
preference tofalse
(Firefox bug 1690308).
Changes for add-on developers
No changes.