Firefox 54.0: find out what is new


Firefox 54.0 has been released on June 13, 2017 to the stable channel. The new version is offered through the Firefox web browser’s automatic update functionality, and also provided as a direct download from Mozilla’s website.

All other Firefox channels, those are Beta, Nightly and ESR, are also updated. Mozilla did remove the Aurora channel from the release cycle when Firefox 53 was released.

Firefox Beta is promoted to version 55, Firefox Nightly to version 56, and Firefox ESR to version 52.2

Executive Summary

  • Mozilla enabled multiple content processes for Firefox’s multi-process architecture for the majority of eligible systems. The number has been raised from 1 to 4 content processes.

Firefox 54.0 download and update

firefox 54.0

Firefox Stable is configured by default to check for updates automatically. The browser’s automatic update feature will pick up the Firefox 54.0 update automatically, download it, and install it on most Firefox systems.

The update check is not in realtime, but you may run it at any time manually in the following way:

  • Tap on the Alt-key on the keyboard, and select Help > About Firefox from the menu.

Firefox queries Mozilla’s servers for update information. Depending on how the browser is configured, if an update is found it may be downloaded and installed directly, or on user request.

Direct download links for Firefox installation files:

  • Firefox Stable download
  • Firefox Beta download
  • Nightly download
  • Firefox ESR download
  • Firefox unbranded builds information

Firefox 54.0 Changes

Support for multiple content processes

firefox multiple content processes

The big new feature of Firefox 54.0 is support for multiple content processes. Firefox’s multi-process architecture has been integrated in previous versions of the Firefox browser, but up until now with only one content process.

What this means is that all websites and services open in Firefox at any time use the same content process. Still good in terms of reliability of the browser as the browser ui is running in a separate process, but not as good as separating these into multiple content processes.

Chrome for instance uses one process per site. Firefox won’t do that, and the main reason why is that it impacts performance and memory use too much.

Mozilla picked four content processes as the default for the switch. So, once Firefox is updated to 54, the bulk of Firefox installations with multi-process enabled, will use four content processes instead of just one.

Firefox users may set the number of content processes manually (read all there is to know about multi-process Firefox in our guide)

  1. Type about:config in the Firefox address bar.
  2. Find dom.ipc.processCount.
  3. Double-click the preference, and change its value to a positive integer. This is the number of content processes that Firefox will use.

Other Firefox 54.0 changes

  • Burmese (my) locale added.
  • Moved mobile bookmarks folder to the main bookmarks folder.
  • Simplified download button and download status panel

Developer Changes

  • 5.1 surround sound playback is enabled by default on all desktop versions of Firefox.
  • The network request summary and the performance analysis view list the transferred size now.
  • Support for VP9 codec in encrypted streams using Clear Key and Widevine added.
  • VP8-encoded webm/video media playback is supported always now, regardless of system performance (previously not allowed if system was considered to be not fast enough).
  • HTTP/1 pipelining is no longer supported. Veteran Firefox users may know related preferences from speed up articles that are a decade old, or older.
  • Developers may add custom devices to the Responsive Device Mode of the developer tools.

Firefox 54.0 for Android

  • Bookmark sync performance has been improved.
  • Bulgarian (bg) and Kabyle (kab) locales added.
  • More reliable audio and video playback.
  • File names are preserved correctly on upload.
  • Formatting for right-to-left languages fixed.

Security updates / fixes

Security information is released after the release of the update. We will add the information once Mozilla makes it available.

Additional information / sources

  • Firefox 54 release notes
  • Firefox 54 Android release notes
  • Add-on compatibility for Firefox 54
  • Firefox 54 for developers
  • Site compatibility for Firefox 54
  • Firefox Security Advisories
  • Firefox Release Schedule

Now Read: The state of Mozilla Firefox