Information and links to do with Firefox 75. This may be useful for Mozilla contributors actively working on the release. It is also a record for future reference. About the 75 release. Release owner: Pascal Chevrel(:pascalc) Corresponding ESR release: 68.7.0; Milestones document for the 74 cycle timeline from Nightly to release.
To prevent Firefox from automatically updating itself after you install an older version, you'll need to change your Firefox update settings: In the Menu bar at the top of the screen, click Firefox and select Preferences. Click the menu button and select Options. In the General panel, go to the Firefox Updates section. Mozilla has released an update for Firefox 86 with Firefox 86.0.1. As is usually the case with Firefox, this minor update of a recently released new major version is a bugfix release. Firefox 86.0.1 does not include new functionality, but fixes minor errors in its predecessor.
This article provides information about the changes in Firefox 75 that will affect developers. Firefox 75 was released on April 7, 2020.
See also the accompanying hacks post — Firefox 75: Ambitions for April.
Changes for web developers
Developer tools
- It is now possible to resize the rectangle of the Measuring Tool (bug 1152321).
- In the inspector, you can now use XPath expressions to locate elements, in addition to locating elements using CSS selectors as before (bug 963933).
- You can now filter WebSocket messages using regular expressions, in addition to plain text search, by writing the regular expression in slashes (bug 1593837).
HTML
- The
loading
attribute of the<img>
element has now been implemented. This string value can be used to specify that the image should be lazily loaded, by setting its value tolazy
(bug 1542784). - The value of the
<style>
element'stype
attribute is now restricted totext/css
only, as per the spec (bug 1614329).
CSS
- Support for the
min()
,max()
, andclamp()
functions has been implemented (bug 1519519). - The
all
value of thetext-decoration-skip-ink
property has been added (bug 1611965)
Accessibility
The new roles and objects related to ARIA annotations are now exposed in Firefox, on Windows and Linux (bear in mind that these still won't be usable until screenreaders start to support them):
aria-description
(bug 1608961).role='mark'
androle='suggestion'
(bug 1608965).role='comment'
(bug 1608969).- Multiple IDs on
aria-details
(bug 1608883).
Note: On macOS, we are first waiting for Apple to define what Safari will expose as Apple-dialect attributes to VoiceOver, and will then follow suit.
JavaScript
- Public static class fields are now supported (bug 1535804).
- The
Intl.Locale
class is now supported (bug 1613713). - The
Function.caller
property has been updated to be aligned with the latest ECMAScript spec proposal. Previously throwing aTypeError
, it now returnsnull
if the caller is a strict, async, or generator function (bug 1610206).
Firefox 64 Bit
APIs
DOM
- The
HTMLFormElement
interface has a new method,requestSubmit()
. Unlike the old (and still available)submit()
method,requestSubmit()
acts as if a specified submit button has been clicked, rather than just sending the form data to the recipient. Thus thesubmit
event is delivered and the form is checked for validity prior to the data being submitted (bug 1613360). - The
submit
event is now represented by an object of typeSubmitEvent
rather than a simpleEvent
.SubmitEvent
includes a newsubmitter
property, which is theElement
that was invoked to trigger the form submission. With this event, you can have a single handler for submit events that can discern which of multiple submit buttons or links was used to submit the form (bug 1588715). - Calling the
click()
method on a detached element (one not part of a DOM tree) now functions normally, leading to aclick
event being sent to it (bug 1610821).
Web animations API
Firefox 75 sees numerous additions to the Web Animations API:
- Implicit to/from keyframes are now supported, as is automatically removing filling animations that have been replaced by other indefinitely filling animations (bug 1618773). This includes enabling of support for:
- The
Animation.timeline
getter,Document.timeline
,DocumentTimeline
, andAnimationTimeline
features are now enabled by default (bug 1619178). - The
Document.getAnimations()
andElement.getAnimations()
methods are now enabled by default (bug 1619821).
Media, Web Audio, and WebRTC
- The
RTCPeerConnection.setLocalDescription()
method can now be called without arguments, in which case the WebRTC runtime will try to create the new local session description itself (bug 1568292).
HTTP
Security
- CSP nonces from non-script sources, such as CSS selectors, and
.getAttribute('nonce')
calls, are now hidden. Instead, check the.nonce
property to access nonces from scripts (bug 1374612).
Plugins
Security
No changes.
WebDriver conformance (Marionette)
- Fixed a bug that always caused Marionette to initialize when Firefox starts-up. It has been limited to the command line argument and environment variable now (bug 1622012).
- Fixed
WebDriver:Print
to no longer add extra margins to the document (bug 1616932). - Changed the preference value for
network.http.speculative-parallel-limit
to0
, to no longer force-disable speculative connections (bug 1617869).
Firefox 75.0 Download
Other
Changes for add-on developers
API changes
- We've added some new settings in
browserSettings
(bug 1286953):browserSettings.zoomSiteSpecific
to control whether zooming is on a per-site or per-tab basisbrowserSettings.zoomFullPage
to control whether zoom is applied to the entire page or to text only.
- The name of the file used when saving a PDF with
tabs.saveAsPDF
can be specified usingtoFileName
in the typetabs.PageSettings
.(bug 1483590)
Manifest changes
- The 'privacy' permission is now optional. (bug 1618399)