Today Mozilla released the new version 50 of Firefox browser. We just made it available in our browser cloud to all our paid and free users. You can now cross-browser test your designs, code and websites in Firefox 50!

Browser testing in Firefox 50

Try Firefox 50 in Browserling now!

Firefox 50 added playback video on more sites without plugins with WebM EME Support for Widevine on Windows and Mac. Improved performance for SDK extensions or extensions using the SDK module loader. Download protection for a large number of executable file types on Windows, Mac and Linux. Increased availability of WebGL to more than 98 percent of users on Windows 7 and newer. Added support for HLS videos via player overlay on Android.

What's new in Firefox 50?

  • Playback video on more sites without plugins with WebM EME Support for Widevine on Windows and Mac.
  • Updates to keyboard shortcuts: Set a preference to have Ctrl+Tab cycle through tabs in recently used order. View a page in Reader Mode by using Ctrl+Alt+R (command+alt+r on Mac).
  • Added download protection for a large number of executable file types on Windows, Mac and Linux.
  • Increased availability of WebGL to more than 98 percent of users on Windows 7 and newer.
  • Added option to Find in page that allows users to limit search to whole words only.
  • Added Guarani (gn) locale.
  • Improved performance for SDK extensions or extensions using the SDK module loader.

What changed in Firefox 50?

  • Blocked versions of libavcodec older than 54.35.1.
  • The link to check for plugin security updates has been removed from the addon manager as Firefox automatically checks for plugin updates.
  • Added a built-in Emoji set for operating systems without native Emoji fonts (Windows 8.0 and lower and Linux).

What changed in Firefox 50 developer tools?

  • The Storage Inspector now lets you delete individual items from IndexedDB object stores.
  • The Box model view is moved into the Computed view.
  • The Memory tool is enabled by default.
  • The Web Console now displays stack traces for XHR or Fetch() network requests.
  • The Web Console now understands source maps.

What changed in Firefox 50 HTML, DOM, CSS, HTTP, SVG and JavaScript implementation?

  • The default style of HTML element <bdo> now sets unicode-bidi with the isolate-override value.
  • The experimental (and deprecated) SPDY 3.1 is now disabled by default.
  • The non-standard CSS :-moz-full-screen-ancestor pseudo-class selector has been removed.
  • CSS border-radiused corners with dashed and dotted styles are now rendered with the specified style instead of a solid style.
  • The ES2015 JavaScript Symbol.hasInstance property has been implemented.
  • Setting the <track> element's src attribute now works correctly.
  • The referrerpolicy attribute on <area>, <a>, <img>, <iframe> and <link> elements is now available by default.

What silly bugs were fixed in Firefox 50?

  • Fixed rendering of dashed and dotted borders with rounded corners (border-radius).
  • Login cookies are now saved for sites with a high number of cookies (Bug 1264192).

What security issues were fixed in Firefox 50?

  • API key (glocation) in broadcast protected with signature-level permission can be accessed by an application installed beforehand that defines the same permissions.
  • Write to arbitrary file with Mozilla Updater and Maintenance Service using updater.log hardlink.
  • SSL indicator can mislead the user about the real URL visited.
  • Integer overflow leading to a buffer overflow in nsScriptLoadHandler.
  • Heap-buffer-overflow WRITE in rasterize_edges_1.
  • 64-bit NPAPI sandbox isn't enabled on fresh profile.
  • heap-use-after-free in nsRefreshDriver.
  • Same-origin policy violation using local HTML file and saved shortcut file.
  • Mozilla Maintenance Service: Ability to read arbitrary files as SYSTEM.
  • Memory safety bugs fixed in Firefox 50 and Firefox ESR 45.5.
  • WebExtensions can access the mozAddonManager API and use it to gain elevated privileges.
  • windows.create schema doesn't specify "format": "relativeUrl".
  • data: URL can inherit wrong origin after an HTTP redirect.
  • Incorrect argument length checking in JavaScript.
  • Private browsing browser traces (Android) in browser.db and wal file.
  • Add-ons update must verify IDs match between current and new versions.
  • Canvas filters allow feDisplacementMaps to be applied to cross-origin images, allowing timing attacks on them.
  • select dropdown menu can be used for URL bar spoofing on e10s.
  • Firefox AuthToken in broadcast protected with signature-level permission can be accessed by an application installed beforehand that defines the same permissions.
  • Insufficient timing side-channel resistance in divSpoiler.
  • Firefox for Android location bar spoofing using fullscreen.
  • Probe browser history via HSTS/301 redirect + CSP.
  • Sidebar bookmark can have reference to chrome window.
  • Memory safety bugs fixed in Firefox 50.
  • heap-use-after-free in nsINode::ReplaceOrInsertBefore.
  • Possible integer overflow to fix inside XML_Parse in Expat.
  • URL parsing causes crash.
  • Arbitrary target directory for result files of update process.

What's remained unresolved in Firefox 50?

  • Firefox fails to log into Firefox Accounts or Sync if browser is set to "Never Remember History".

Happy cross-browser testing in Firefox 50!