Firefox 47 for developers

• User-agent spoofing from the Responsive mode
• Retaining paths panel in memory tool
• Service workers and Push API debugging
  • about:debugging dashboard for workers
  • Cached requests are now shown in Network Monitor
  • Support for cache storage in Storage Inspector
• Ability to filter Storage Inspector entries
• Console now detects incomplete input and switches multi-line mode
• Updated breakpoint style in Debugger
• Prevent panels from hiding automatically using the Browser Toolbox, to aid browser and add-on debugging
• Font inspector has been disabled by default
• 3D view has been removed
• Developer tools theme refresh
• Disable the Font Panel (Firefox bug 1247723).

No change.

• Support for the ::backdrop pseudo-element has been added (Firefox bug 1064843).
• The case-insensitive modifier i (like in [foo=bar i]) for attribute selectors has been implemented (Firefox bug 888190).
• An experimental implementation of CSS Mask Image properties landed. For the moment, this will only be available on Nightly versions of Firefox.y: shorthand version of mask, as well as mask-repeat, mask-position, mask-size are now available (Firefox bug 686281).
• The clip-path property now experimentally supports polygon(), ellipse(), and circle() on HTML elements (does not support inset() and path()), behind the pref layout.css.clip-path-shapes.enabled that defaults to false (Firefox bug 1075457). Interpolation (and therefore animation) of these values is not yet supported.
• Our still experimental grid implementation has been updated:
  • align-content: normal behaves now as stretch for grid containers (Firefox bug 1237754).
  • The order of column/row values for grid, grid-template, and grid-gap properties has been swapped (Firefox bug 1251999).
• The display-mode media feature is now supported (Firefox bug 1104916).
• The value true of text-align and text-align-last has been renamed to unsafe (Firefox bug 1250342).

• The new ES2017 Object.values() and Object.entries() methods have been implemented (Firefox bug 1232639).
• The deprecated, old Proxy API (Proxy.create and Proxy.createFunction) now presents a deprecation warning in the console and will be removed in a future version. Use the standard Proxy object instead (Firefox bug 892903).
• Support for the deprecated non-standard flags argument of String.prototype.match/search/replace has been dropped in non-release builds (Firefox bug 1245801).
• As per the new ES2016 specification, the Proxy enumerate trap for for...in statements has been removed (Firefox bug 1246318).
• The Array.prototype.indexOf() and Array.prototype.lastIndexOf() methods (and their TypedArray equivalents) have been updated to never return -0 as per the ECMAScript specification (Firefox bug 1242043).

DOM & HTML DOM

• The property Document.scrollingElement has been implemented behind the pref dom.document.scrollingElement.enabled that defaults to false (Firefox bug 1153322).

WebGL

No change.

IndexedDB

• The IDBKeyRange.includes() method has been implemented (Firefox bug 1251498).

Service Worker and related APIs

• The Request() constructor can now accept a referrer option in its init object (Firefox bug 1251448).
• The Request.referrerPolicy property is now supported (Firefox bug 1251872).
• Service workers and Push have been disabled in the Firefox 45 Extended Support Release (ESR) (Firefox bug 1232029).

WebRTC

• Support for the RTCIceServer dictionary has been updated in keeping with revisions to the WebGL 1.0 specification by adding support for the credentialType property. This property is a string that specifies whether the credential is a password or a token. Currently, Firefox only supports "password".

New APIs

No change.

Others

• Cache.add() and Cache.addAll() now raises a TypeError exception if the response status is not in the 200 range (Firefox bug 1244764).
• The App installation and management APIs (navigator.mozApps.*) are no longer exposed to non-Firefox OS platforms (Firefox bug 1238576).
• Web Crypto API methods can now use the RSA-PSS cryptographic algorithm (Firefox bug 1191936).
• The Permissions API has had the Permissions.revoke() method added (Firefox bug 1197461).
• The Browser API, which extends the functionality of <iframe>s to allow the creation of frames for displaying web content using HTML — and was previously only available in Firefox OS — is now available to desktop chrome code too (Firefox bug 1238160).
• The Notification API's requestPermission() method has been updated from a callback to a promised-based syntax (Firefox bug 1241278).
• The Fullscreen API has been updated to the latest spec and unprefixed. Some methods have been renamed or have seen their capitalization changed (Firefox bug 743198). Note that this is behind the full-screen-api.unprefix.enabled preference, defaulting to false (Firefox bug 1268749).

• Now WAV file with u-law compression encoding can be played(Firefox bug 851530).
• Widevine Content Decryption Module provided by Google Inc. is available via the Encrypted Media Extensions API for use with MP4 (only; see Firefox bug 1257716 for EME-with-WebM support) on Windows Vista and later and on Mac OS X enabling migration off Silverlight (Firefox bug 1265270).

• The default value of the Accept header for images is now */* instead of image/png,image/*;q=0.8,*/*;q=0.5 (Firefox bug 1249474).

No change.

• URLs with the view-source: protocol don't open the View Source tool anymore when used from a Web page (Firefox bug 1172165).
• The Firefox click-to-activate plugin whitelist has been removed: only Flash doesn't need to be clicked to be activated (Firefox bug 1263630).

• The CSS tokenizer is now available in JavaScript for add-ons (Firefox bug 1152033).

The FUEL JavaScript library, introduced back in Firefox 3, has been removed. This library was designed to aid in add-on development and with the introduction of the Add-on SDK and, now, by WebExtensions support, is no longer useful. (Firefox bug 1090880)

No change.

No change.

No change.

No change.