What’s New
- NEW
Default search engine changed to Yandex for Belarusian, Kazakh, and Russian locales
- NEW
Improved search bar (en-US only)
- NEW
Firefox Hello real-time communication client
- NEW
Easily switch themes/personas directly in the Customizing mode
- NEW
Wikipedia search now uses HTTPS for secure searching (en-US only)
- NEW
Implementation of HTTP/2 (draft14) and ALPN
- NEW
Recover from a locked Firefox process in the "Firefox is already running" dialog on Windows
- CHANGED
Disabled SSLv3
- CHANGED
Proprietary window.crypto properties/functions re-enabled (to be removed in Firefox 35)
- CHANGED
Firefox signed by Apple OS X version 2 signature
- HTML5
ECMAScript 6 WeakSet Implemented
- HTML5
JavaScript Template Strings Implemented
- HTML5
CSS3 Font variants and features control (e.g. kerning) implemented
- HTML5
WebCrypto: RSA-OAEP, PBKDF2 and AES-KW support
- HTML5
WebCrypto: wrapKey and unwrapKey implemented
- HTML5
WebCrypto: Import/export of JWK-formatted keys
- HTML5
matches() DOM API implemented (formerlymozMatchesSelector())
- HTML5
Performance.now() for workers implemented
- HTML5
WebCrypto: ECDH support
- DEVELOPER
Link Removed: Create, edit, and test a new Web application from your browser
- DEVELOPER
Highlight all nodes that match a given selector in the Style Editor and the Inspector's Rules panel
- DEVELOPER
Improved User Interface of the Profiler
- DEVELOPER
console.table function added to web console
- FIXED
CSS transitions start correctly when started at the same time as changes to display, position, overflow, and similar properties
- FIXED
Various security fixes
ref:What’s New
Known Issues
- NEW
Firefox Hello with new rooms-based conversations model
- NEW
New search UI improved and enabled for more locales
- NEW
Access the Link Removed from the Tools menu and optional toolbar button
- NEW
Built-in support for H264 (MP4) on Mac OS X Snow Leopard (10.6) and newer through native APIs
- NEW
Use tiled rendering on OS X
- NEW
Improved high quality image resizing performance
- NEW
Improved handling of dynamic styling changes to increase responsiveness
- NEW
Implemented HTTP Public Key Pinning Extension (for enhanced authentication of encrypted connections)
- HTML5
Added support for the CSS Font Loading API
- HTML5
Resource Timing API implemented
- HTML5
CSS filters enabled by default
- HTML5
Changed JavaScript 'let' semantics to match the ES6 specification
- DEVELOPER
Support for inspecting ::before and ::after pseudo elements
- DEVELOPER
Computed view: Nodes matching the hovered selector are now highlighted
- DEVELOPER
Network Monitor: New request/response headers view (more info)
- DEVELOPER
Added support for the EXT_blend_minmax WebGL extension
- FIXED
Show DOM Properties context menu item in inspector
- FIXED
Reduced resource usage for scaled images
- FIXED
PDF.js updated to version 1.0.907
- FIXED
Non-HTTP(S) XHR now returns correct status code
- FIXED
Various security fixes
- UNRESOLVED
Sometimes images don't display when hovered over (seebug 1083113)
- UNRESOLVED
WebGL games might not display some textures (see bug 1113633)
- UNRESOLVED
Issues affecting RTL in Hello can be found here
What’s New
Known Issues
- FIXED
35.0.1 - With the Enhanced Steam extension, Firefox could crash (1123732)
- FIXED
35.0.1 - Fix a potential startup crash (1122367)
- FIXED
35.0.1 - Kerberos authentication did not work with alias (1108971)
- FIXED
35.0.1 - SVG / CSS animation had a regression causing rendering issues on websites like openstreemap.org (1083079)
- FIXED
35.0.1 - On Godaddy webmail, Firefox could crash (1113121)
- FIXED
35.0.1 - document.baseURI did not get updated to document.location after base tag was removed from DOM for site with a CSP (1121857)
- FIXED
35.0.1 - With a Right-to-left (RTL) version of Firefox, the text selection could be broken (1104036)
- FIXED
35.0.1 - CSP had a change in behavior with regard to case sensitivity resources loading (1122445)
- NEW
Firefox Hello with new rooms-based conversations model
- NEW
New search UI improved and enabled for more locales
- NEW
Access the Link Removed from the Tools menu and optional toolbar button
- NEW
Built-in support for H264 (MP4) on Mac OS X Snow Leopard (10.6) and newer through native APIs
- NEW
Improved handling of dynamic styling changes to increase responsiveness
- NEW
Use tiled rendering on OS X
- NEW
Improved high quality image resizing performance
- HTML5
Changed JavaScript 'let' semantics to conform better to the ES6 specification
- HTML5
Resource Timing API implemented
- HTML5
CSS filters enabled by default
- HTML5
Added support for the CSS Font Loading API
- DEVELOPER
Support for inspecting ::before and ::after pseudo elements
- DEVELOPER
Computed view: Nodes matching the hovered selector are now highlighted
- DEVELOPER
Network Monitor: New request/response headers view (more info)
- DEVELOPER
Added support for the EXT_blend_minmax WebGL extension
- FIXED
Various security fixes
- FIXED
Show DOM Properties context menu item in inspector
- FIXED
Reduced resource usage for scaled images
- FIXED
PDF.js updated to version 1.0.907
- FIXED
Non-HTTP(S) XHR now returns correct status code
- UNRESOLVED
WebGL games might not display some textures (see bug 1113633)
- UNRESOLVED
Sometimes images don't display when hovered over (seebug 1083113)
- UNRESOLVED
Issues affecting RTL in Hello can be found here
What’s New
Known Issues
- NEW
Pinned tiles on the new tab page can be synced
- NEW
Support for the full HTTP/2 protocol. HTTP/2 enables a faster, more scalable, and more responsive web.
- NEW
Locale added: Uzbek (uz)
- CHANGED
-remote option removed
- CHANGED
No longer accept insecure RC4 ciphers whenever possible
- CHANGED
Phasing out Certificates with 1024-bit RSA Keys
- CHANGED
Shut down hangs will now show the crash reporter before exiting the program
- CHANGED
Add-on Compatibility
- HTML5
Support for the ECMAScript 6 Symbol data type added
- HTML5
unicode-range CSS descriptor implemented
- HTML5
CSSOM-View scroll behavior implemented allowing smooth scrolling of content without custom libraries
- HTML5
object-fit and object-position implemented.
Defines how and where the content of a replaced element is displayed
- HTML5
isolation CSS property implemented.
Create a new stacking context to isolate groups of boxes to control which blend together
- HTML5
CSS3 will-change property implemented.
Hints the browser of elements that will be modified. The browser will perform some performance optimization for these
- HTML5
Changed JavaScript 'const' semantics to conform better to the ES6 specification.
The const declaration is now b-scoped and requires an initializer. It also can not be redeclared anymore.
- HTML5
Improved ES6 generators for better performance
- DEVELOPER
Eval sources now appear in the Debugger
Debug JavaScript code that is evaluated dynamically, either as a string passed to eval() or as a string passed to the Function constructor
- DEVELOPER
DOM Promises inspection
- DEVELOPER
Inspector: More paste options in markup view
- FIXED
CSS gradients work on premultiplied colors
- FIXED
Fix some unexpected logout from Facebook or Google after restart
- FIXED
Various security fixes
- UNRESOLVED
Style Editor: Extra white space appearing above the editor for a sourcemapped scss file (1128747)
What’s New
Known Issues
- FIXED
36.0.1 - Disable the usage of the ANY DNS query type (1093983)
- FIXED
36.0.1 - Fixed a startup crash with EMET (1137050)
- FIXED
36.0.1 - Hello may become inactive until restart (1137469)
- FIXED
36.0.1 - Print preferences may not be preserved (1136855)
- FIXED
36.0.1 - Hello contact tabs may not be visible (1137141)
- FIXED
36.0.1 - Accept hostnames that include an underscore character ("_") (1136616)
- FIXED
36.0.1 - WebGL may use significant memory with Canvas2d (1137251)
- FIXED
36.0.1 - Option -remote has been restored (1080319)
- FIXED
36.0.1 - Fix a top crash
- NEW
Pinned tiles on the new tab page can be synced
- NEW
Support for the full HTTP/2 protocol. HTTP/2 enables a faster, more scalable, and more responsive web.
- NEW
Locale added: Uzbek (uz)
- CHANGED
-remote option removed
- CHANGED
No longer accept insecure RC4 ciphers whenever possible
- CHANGED
Phasing out Certificates with 1024-bit RSA Keys
- CHANGED
Shut down hangs will now show the crash reporter before exiting the program
- CHANGED
Add-on Compatibility
- HTML5
Support for the ECMAScript 6 Symbol data type added
- HTML5
unicode-range CSS descriptor implemented
- HTML5
CSSOM-View scroll behavior implemented allowing smooth scrolling of content without custom libraries
- HTML5
object-fit and object-position implemented.
Defines how and where the content of a replaced element is displayed
- HTML5
isolation CSS property implemented.
Create a new stacking context to isolate groups of boxes to control which blend together
- HTML5
CSS3 will-change property implemented.
Hints the browser of elements that will be modified. The browser will perform some performance optimization for these
- HTML5
Improved ES6 generators for better performance
- HTML5
Changed JavaScript 'const' semantics to conform better to the ES6 specification.
The const declaration is now b-scoped and requires an initializer. It also can not be redeclared anymore.
- DEVELOPER
Eval sources now appear in the Debugger
Debug JavaScript code that is evaluated dynamically, either as a string passed to eval() or as a string passed to the Function constructor
- DEVELOPER
DOM Promises inspection
- DEVELOPER
Inspector: More paste options in markup view
- FIXED
Various security fixes
- FIXED
CSS gradients work on premultiplied colors
- FIXED
Fix some unexpected logout from Facebook or Google after restart
- UNRESOLVED
Style Editor: Extra white space appearing above the editor for a sourcemapped scss file (1128747)
- UNRESOLVED
For users who removed the Share & Hello buttons, this new version brings them back unexpectedly (1136300)
- UNRESOLVED
Firefox Hello does not work for link generators if there is no camera installed (1106941)
What’s New
Known Issues
- FIXED
36.0.3: Security fixes for issues disclosed at HP Zero Day Initiative's Pwn2Own contest
- NEW
Pinned tiles on the new tab page can be synced
- NEW
Support for the full HTTP/2 protocol. HTTP/2 enables a faster, more scalable, and more responsive web.
- NEW
Locale added: Uzbek (uz)
- CHANGED
-remote option removed
- CHANGED
No longer accept insecure RC4 ciphers whenever possible
- CHANGED
Phasing out Certificates with 1024-bit RSA Keys
- CHANGED
Shut down hangs will now show the crash reporter before exiting the program
- CHANGED
Add-on Compatibility
- HTML5
Support for the ECMAScript 6 Symbol data type added
- HTML5
unicode-range CSS descriptor implemented
- HTML5
CSSOM-View scroll behavior implemented allowing smooth scrolling of content without custom libraries
- HTML5
object-fit and object-position implemented.
Defines how and where the content of a replaced element is displayed
- HTML5
isolation CSS property implemented.
Create a new stacking context to isolate groups of boxes to control which blend together
- HTML5
CSS3 will-change property implemented.
Hints the browser of elements that will be modified. The browser will perform some performance optimization for these
- HTML5
Improved ES6 generators for better performance
- HTML5
Changed JavaScript 'const' semantics to conform better to the ES6 specification.
The const declaration is now b-scoped and requires an initializer. It also can not be redeclared anymore.
- DEVELOPER
Eval sources now appear in the Debugger
Debug JavaScript code that is evaluated dynamically, either as a string passed to eval() or as a string passed to the Function constructor
- DEVELOPER
DOM Promises inspection
- DEVELOPER
Inspector: More paste options in markup view
- FIXED
36.0.1 - Hello may become inactive until restart (1137469)
- FIXED
36.0.1 - Print preferences may not be preserved (1136855)
- FIXED
36.0.1 - Hello contact tabs may not be visible (1137141)
- FIXED
36.0.1 - Disable the usage of the ANY DNS query type (1093983)
- FIXED
36.0.1 - Fixed a startup crash with EMET (1137050)
- FIXED
36.0.1 - WebGL may use significant memory with Canvas2d (1137251)
- FIXED
36.0.1 - Accept hostnames that include an underscore character ("_") (1136616)
- FIXED
36.0.1 - Option -remote has been restored (1080319)
- FIXED
36.0.1 - Fix a top crash
- FIXED
Various security fixes
- FIXED
CSS gradients work on premultiplied colors
- FIXED
Fix some unexpected logout from Facebook or Google after restart
- UNRESOLVED
Style Editor: Extra white space appearing above the editor for a sourcemapped scss file (1128747)
- UNRESOLVED
For users who removed the Share & Hello buttons, this new version brings them back unexpectedly (1136300)
- UNRESOLVED
Firefox Hello does not work for link generators if there is no camera installed (1106941)
What’s New
Known Issues
- FIXED
36.0.4: Security fixes for issues disclosed at HP Zero Day Initiative's Pwn2Own contest
- NEW
Pinned tiles on the new tab page can be synced
- NEW
Support for the full HTTP/2 protocol. HTTP/2 enables a faster, more scalable, and more responsive web.
- NEW
Locale added: Uzbek (uz)
- CHANGED
No longer accept insecure RC4 ciphers whenever possible
- CHANGED
Phasing out Certificates with 1024-bit RSA Keys
- CHANGED
Shut down hangs will now show the crash reporter before exiting the program
- CHANGED
Add-on Compatibility
- HTML5
Support for the ECMAScript 6 Symbol data type added
- HTML5
unicode-range CSS descriptor implemented
- HTML5
CSSOM-View scroll behavior implemented allowing smooth scrolling of content without custom libraries
- HTML5
object-fit and object-position implemented.
Defines how and where the content of a replaced element is displayed
- HTML5
isolation CSS property implemented.
Create a new stacking context to isolate groups of boxes to control which blend together
- HTML5
CSS3 will-change property implemented.
Hints the browser of elements that will be modified. The browser will perform some performance optimization for these
- HTML5
Improved ES6 generators for better performance
- HTML5
Changed JavaScript 'const' semantics to conform better to the ES6 specification.
The const declaration is now b-scoped and requires an initializer. It also can not be redeclared anymore.
- DEVELOPER
Eval sources now appear in the Debugger
Debug JavaScript code that is evaluated dynamically, either as a string passed to eval() or as a string passed to the Function constructor
- DEVELOPER
DOM Promises inspection
- DEVELOPER
Inspector: More paste options in markup view
- FIXED
36.0.3: Security fixes for issues disclosed at HP Zero Day Initiative's Pwn2Own contest
- FIXED
36.0.1 - Hello may become inactive until restart (1137469)
- FIXED
36.0.1 - Print preferences may not be preserved (1136855)
- FIXED
36.0.1 - Hello contact tabs may not be visible (1137141)
- FIXED
36.0.1 - Disable the usage of the ANY DNS query type (1093983)
- FIXED
36.0.1 - Fixed a startup crash with EMET (1137050)
- FIXED
36.0.1 - WebGL may use significant memory with Canvas2d (1137251)
- FIXED
36.0.1 - Accept hostnames that include an underscore character ("_") (1136616)
- FIXED
36.0.1 - Option -remote has been restored (1080319)
- FIXED
36.0.1 - Fix a top crash
- FIXED
Various security fixes
- FIXED
CSS gradients work on premultiplied colors
- FIXED
Fix some unexpected logout from Facebook or Google after restart
- UNRESOLVED
Style Editor: Extra white space appearing above the editor for a sourcemapped scss file (1128747)
- UNRESOLVED
For users who removed the Share & Hello buttons, this new version brings them back unexpectedly (1136300)
- UNRESOLVED
Firefox Hello does not work for link generators if there is no camera installed (1106941)
ref:What’s New
- NEW
Heartbeat user rating system - your feedback about Firefox
- NEW
Yandex set as default search provider for the Turkish locale
- NEW
Bing search now uses HTTPS for secure searching
- NEW
Improved protection against site impersonation via OneCRL centralized certificate revocation
- NEW
Opportunistically encrypt HTTP traffic where the server supports HTTP/2 AltSvc
- CHANGED
Disabled insecure TLS version fallback for site security
- CHANGED
Extended SSL error reporting for reporting non-certificate errors
- CHANGED
TLS False Start optimization now requires a cipher suite using AEAD construction
- CHANGED
Improved certificate and TLS communication security by removing support for DSA
- CHANGED
Improved performance of WebGL rendering on Windows
- HTML5
Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube (Windows Vista or later only)
- HTML5
Added support for CSS display:contents
- HTML5
IndexedDB now accessible from worker threads
- HTML5
New SDP/JSEP implementation in WebRTC
- DEVELOPER
Link Removed
- DEVELOPER
New Inspector animations panel to control element animations
- DEVELOPER
New Security Panel included in Network Panel
- DEVELOPER
Debugger panel support for chrome:// and about:// URIs
- DEVELOPER
Added logging of weak ciphers to the web console
- FIXED
Various security fixes
What’s New
- Reference: Link Removed
- CHANGED
Disabled HTTP/2 AltSvc
- FIXED
Start-up crash due to graphics hardware and third party software
- FIXED
Various security fixes
What’s New
- Reference: Release notes for Firefox 37.0.1
- FIXED
Google Maps may render incorrectly in some cases
- FIXED
Stability fixes for select graphics hardware and feature sets
- FIXED
Various security fixes
Firefox Notes
Version 38.0, first offered to Release channel users on May 12, 2015
What’s New
- NEW
New tab-based preferences
- NEW
Ruby annotation support
- NEW
Base for the next ESR release.
- CHANGED
autocomplete=off is no longer supported for username/password fields
- CHANGED
URL parser avoids doing percent encoding when setting the Fragment part of the URL, and percent decoding when getting the Fragment in line with the URL spec
- CHANGED
RegExp.prototype.source now returns "(?" instead of the empty string for empty regular expressions
- CHANGED
Improved page load times via speculative connection warmup
- HTML5
WebSocket now available in Web Workers
- HTML5
BroadcastChannel API implemented
- HTML5
Implemented srcset attribute and <picture> element for responsive images
- HTML5
Implemented DOM3 Events KeyboardEvent.code
- HTML5
Mac OS X: Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube
- HTML5
Implemented Encrypted Media Extensions (EME) API to support encrypted HTML5 video/audio playback (Windows Vista or later only)
- HTML5
Automatically download Adobe Primetime Content Decryption Module (CDM) for DRM playback through EME (Windows Vista or later only)
- DEVELOPER
Optimized-out variables are now visible in Debugger UI
- DEVELOPER
XMLHttpRequest logs in the web console are now visually labelled and can be filtered separately from regular network requests
- DEVELOPER
WebRTC now has multistream and renegotiation support
- DEVELOPER
copy command added to console
- FIXED
Various security fixes
What’s New
Known Issues
Reference: Release notes for Firefox 38.0
- FIXED
Systems with first generation NVidia Optimus graphics cards may crash on start-up
- FIXED
Users who import cookies from Google Chrome can end up with broken websites
- FIXED
WebRTC H264 video streams from CiscoSpark native clients are not decoded correctly. (Fixed in Firefox ESR 38.0.1; was already fixed in Firefox 38.0)
- FIXED
Large animated images may fail to play and may stop other images from loading
- UNRESOLVED
Responsive images do not update when the enclosing viewport changes
What’s New
Known Issues
Reference: Release notes for Firefox 38.0.1
- NEW
Keep track of articles and videos with Pocket
- NEW
Clean formatting for articles and blog posts with Reader View
- NEW
Share the active tab or window in a Hello conversation
- FIXED
A race condition that would cause Firefox to stop painting when switching tabs (bug 1067470)
- FIXED
Fixed graphics performance when using the built-in VGA driver on Windows 7 (Bug 1165732)
- UNRESOLVED
Responsive images do not update when the enclosing viewport changes
What’s New
- NEW
Share Hello URLs with social networks
- NEW
Project Silk: Smoother animation and scrolling (Mac OS X)
- NEW
Support for 'switch' role in ARIA 1.1 (web accessibility)
- NEW
SafeBrowsing malware detection lookups enabled for downloads (Mac OS X and Linux)
- NEW
Support for new Unicode 8.0 skin tone emoji
- CHANGED
Removed support for insecure SSLv3 for network communications
- CHANGED
Disable use of RC4 except for temporarily whitelisted hosts
- CHANGED
The malware detection service for downloads now covers common Mac file types (Bug 1138721)
- CHANGED
Performance of displaying dashed lines is improved (Mac OS X) (Bug 1123019)
- HTML5
List-style-type now accepts a string value
- HTML5
Enable the Fetch API for network requests from dedicated, shared and service workers
- HTML5
Cascading of CSS transitions and animations now matches the current spec
- HTML5
Implement <link rel="preconnect">allowing anticipation of a future connection without revealing any information
- HTML5
Added support for Link Removed
- DEVELOPER
Drag and drop enabled for nodes in Inspector markup view
- DEVELOPER
Webconsole input history persists even after closing the toolbox
- DEVELOPER
Cubic bezier tooltip now shows a gallery of timing-function presets for use with CSS animations
- DEVELOPER
localhost is now available offline for WebSocket connections
- FIXED
Improve performance for IPv6 fallback to IPv4
- FIXED
Fix incomplete downloads being marked as complete by detecting broken HTTP1.1 transfers
- FIXED
The Security state indicator on a page now correctly ignores loads caused by previous pages
- FIXED
Fixed an issue where a Hello conversation window would sometimes fail to open
- FIXED
A regression that could lead to Flash not displaying has been fixed
- FIXED
Update to Link Removed
- FIXED
Various security fixes
Firefox Notes
Version 40.0, first offered to Release channel users on August 11, 2015
Check out "What’s New" and "Known Issues" for this version of Firefox below. As always, you’re encouraged to tell us what you think, or file a bug in Bugzilla. If interested, please see the Link Removed in this release.
We'd also like to extend a special thank you to all of the new Mozillians who contributed to this release of Firefox!
What’s New
Known Issues
- NEW
Support for Windows 10
- NEW
Added protection against unwanted software downloads
- NEW
User can receive suggested tiles in the new tab page based on categories Firefox matches to browsing history (en-US only).
- NEW
Hello allows adding a link to conversations to provide context on what the conversation will be about
- NEW
New style for add-on manager based on the in-content preferences style
- NEW
Improved scrolling, graphics, and video playback performance with off main thread compositing (GNU/Linux only)
- NEW
Graphic blocklist mechanism improved: Firefox version ranges can be specified, limiting the number of devices blocked
- CHANGED
Add-on extensions that are not signed by Mozilla willdisplay a warning
- CHANGED
NPAPI Plug-in performance improved via asynchronous initialization
- CHANGED
Smoother animation and scrolling with hardware vsync(Windows only)
- CHANGED
JPEG images use less memory when scaled and can be painted faster
- CHANGED
Sub-resources Link Removed, thus protecting users from inadvertently disclosing login data
- HTML5
IndexedDB transactions are now non-durable by default
- HTML5
Implemented AudioBufferSourceNode.detune to modulate playback rate in cents, a logarithmic unit of measure used for musical intervals
- DEVELOPER
Improved Performance tools in the developer tools:Waterfall view, Call Tree view and a Flame Chart view
- DEVELOPER
New rules view tooltip in the Inspector to tweak CSS Filter values
- DEVELOPER
Console API messages from SharedWorker and ServiceWorker are now displayed in web console
- DEVELOPER
New page ruler highlighting tool that displays lightweight horizontal and vertical rules on a page
- DEVELOPER
Inspector now searches across all content frames in a page
- FIXED
Kannada text does not display properly in built-in pdf viewer
- FIXED
Various security fixes
- UNRESOLVED
If Firefox is restarted from an add-on install notification, on-going private browsing downloads might be canceled without warning (1185294)
What’s New
- Reference: Release notes for Firefox 40.0
- NEW
Enabled API allowing Windows 10 users to open settings dialog (1193196)
- FIXED
mozalloc.lib was missing from the xulrunner package (1168291)
- FIXED
Fix a startup crash with some combination of hardware and drivers (1160295)
What’s New
- Reference: Release notes for Firefox 40.0.2
- CHANGED
Disable the asynchronous plugin initialization (1198590)
- FIXED
Fix a segmentation fault in the GStreamer support (GNU/Linux) (1145230)
- FIXED
Fix a startup crash when using DisplayLink (Windows Only) (1195844)
- FIXED
Fix a regression with some Japanese fonts used in the <input> field (1194055)
- FIXED
On some sites, the selection in a select combox box using the mouse could be broken (1194733)
- FIXED
Some search partner codes were missing (1195683)
- FIXED
Various security fixes