files/en-us/mozilla/firefox/releases/60/index.md
This article provides information about the changes in Firefox 60 that will affect developers. Firefox 60 was released on May 9, 2018.
Firefox's new parallel CSS engine — also known as Quantum CSS or Stylo — which was first enabled by default in Firefox 57 for desktop, has now been enabled in Firefox for Android.
Alt + Up/Down to Ctrl + Up/Down on Linux and Windows, to avoid clashes with default OS-level shortcuts (see Firefox bug 1413314).var( into a property value and then type a dash (-), any variables you have declared in your CSS will then appear in an autocomplete list.view_source.tab preference has been removed so you can no longer toggle View Source mode between appearing in a new tab or new window. Page sources will always appear in new tabs from now on (Firefox bug 1418403).Pressing the Enter key in designMode and contenteditable now inserts <div> elements when the caret is in an inline element or text node which is a child of a block level editing host — instead of inserting elements like it used to. If you want to use the old behavior on your app, you can do it with document.execCommand() (Firefox bug 1430551).
No changes.
ECMAScript 2015 modules have been enabled by default in (Firefox bug 1438139). See ES6 In Depth: Modules and ES modules: A cartoon deep dive for more information, or consult MDN reference docs:
<script src="main.js" type="module"> and <script nomodule src="fallback.js">import and export statements.The {{jsxref("Array.prototype.values()")}} method has been added again (Firefox bug 1420101). Make sure your code doesn't have any custom implementation of this method.
MakePublicKeyCredentialOptions dictionary object has been renamed PublicKeyCredentialCreationOptions; this change has been made in Firefox (Firefox bug 1436473).dom.workers.enabled pref has been removed, meaning workers can no longer be disabled since (Firefox bug 1434934).KeyboardEvent.keyCode in new applications — use {{domxref("KeyboardEvent.key")}} or {{domxref("KeyboardEvent.code")}} instead.storage option of the {{domxref("IDBFactory.open()")}} method has been deprecated (Firefox bug 1442560).No changes.
No changes.
false now turns off the camera's "in use" indicator light, to help the user more easily see that the camera is not in use (Firefox bug 1299515). See User privacy for more details. See also this blog post.RTCRtpContributingSource and RTCRtpSynchronizationSource objects' timestamps were previously being reported based on values returned by {{jsxref("Date.getTime()")}}. In Firefox 60, these have been fixed to correctly use the Performance Timing API instead (Firefox bug 1433576).NotSupportedError {{domxref("DOMException")}} if the referenced {{domxref("AudioBuffer")}} does not have 1, 2, or 4 channels (Firefox bug 1443228).RTCDataChannel, instead of being an alias for DataChannel. The name DataChannel is no longer supported (Firefox bug 1173851).privacy.resistFingerprinting preference is set to true, the {{domxref("WEBGL_debug_renderer_info")}} WebGL extension will be disabled from now on (Firefox bug 1337157).No changes.
SameSite cookies are now supported (Firefox bug 795346). See {{HTTPHeader("Set-Cookie")}} for more information.The {{httpheader("X-Content-Type-Options")}} header, when set to no-sniff, now follows the specification for JavaScript MIME types. In particular, text/json and application/json are no longer valid values (Firefox bug 1431095).
No changes.
Fetches that include credentials can now share connections with fetches that don't include credentials. For example, if the same origin requests some web fonts as well as some credentialed user data from the same CDN, both could share a connection, potentially leading to a quicker turnaround (Firefox bug 1363284).
No changes.
enabled and disabled values are no longer available (Firefox bug 1405087).-moz-border-top-colors, -moz-border-right-colors, -moz-border-bottom-colors, and -moz-border-left-colors properties have been removed from the platform completely (Firefox bug 1429723).The non-standard expression closure syntax has been removed (Firefox bug 1426519).
No changes.
No changes.
No changes.
Theme API:
headerURL is specified (see Firefox bug 1404688).