Firefox 83 for developers
This article provides information about the changes in Firefox 83 that will affect developers. Firefox 83 was released on November 17, 2020.
Note: See also Firefox 83 is upon us on Mozilla hacks
Changes for web developers
Developer Tools
- When using the
:screenshot
helper command in the Web Console, the--dpr
parameter is no longer ignored when taking a fullscreen screenshot using--fullpage
(Firefox bug 1645284). - Developers can use the
scroll
badge in the Page Inspector to Debug scrollable overflow. Selecting the badge highlights elements that are causing overflow and marks them with theoverflow
badge (Firefox bug 1669129).
HTML/XML
- The
crossorigin
attribute is now supported for<link rel=icon>
(Firefox bug 1661075). - The
displaystyle
attribute is now implemented for all MathML elements (Firefox bug 1666075).
CSS
- The vendor prefixed
:-moz-any()
is now aliased to the standard:is()
CSS pseudo-class function (Firefox bug 1666086). - We've added support for CSS Conic Gradients (Firefox bug 1632351) and (Firefox bug 1175958).
JavaScript
Intl[@@toStringTag]
has been added, returning a default value ofIntl
(recent addition to the ECMA spec). (Firefox bug 1670053)
HTTP
No changes.
APIs
No changes.
WebDriver conformance (Marionette)
- We've removed preliminary support for
WebDriver:SwitchToShadowRoot
, which hasn't been added to the WebDriver specification yet (Firefox bug 1662468). - We fixed a bug in
WebDriver:Back
andWebDriver:Forward
that caused Marionette to hang when the navigation was triggered from within an<iframe>
that gets removed (Firefox bug 1672758).
Changes for add-on developers
No changes.
Older versions
- 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
- Firefox 60 for developers
- Firefox 59 for developers
- Firefox 58 for developers
- Firefox 57 for developers
- Firefox 56 for developers
- Firefox 55 for developers
- Firefox 54 for developers
- Firefox 53 for developers
- Firefox 52 for developers