If you're using Firefox, it should update automatically to version 57. But chances are you're not a Firefox user.

The open-source browser's popularity has been dwindling ever since Google Chrome's launch in 2008.

Mozilla released Version 57 today, and the technology and design shift is so important that they had to give it a special name: Firefox Quantum. Quantum makes a lot of daring promises. But it is not sure that this change in the codebase and interface will be enough to make entrenched Chrome and Safari users switch.

What's new


Everyone and their cat now has a multicore processor. The problem is that most browsers only use one core at a time. With Quantum, Mozilla worked extensively on parallelization in order to make the simultaneous use of several cores possible.

Gecko is the rendering engine made by Mozilla. But in this release, besides a general code optimization, some components have been downright replaced by elements coming from other projects.

For instance, the CSS renderer is now courtesy of the Servo project. It has been dubbed Stylo.

Another in-house language has appeared: Rust.

All these changes result in a reduction of the amount of RAM used: the new Firefox uses 30% less memory than Chrome for the same open tabs.


Changes are not only under the hood, as the tabs' design and the general layout of the interface have been changed in a tremendous way.

New tab

The new tab page now displays news from website you've visited, besides the usual top visited list. Just like Google Now, the new new tab page is focused on content discovery.

Bookmarks library

Bookmarks are now nicely sorted in a panel called your library. The panel appears on the side of the browser window and disappears when it loses focus, but you can pin it to the side if you want an always-on display of your bookmarks.

Built-in screenshot

Firefox screenshot allows you to capture and share parts of the website you're visiting. It includes an upload feature to host your screenshots feely online in Mozilla's cloud.


Another important change is the switch to the WebExtensions format. Firefox is now using the exact same addon format as Google Chrome and its derivatives.

On the one hand, this switch promotes compatibility between browsers, and it makes it easier for extension developers to code in one framework for multiple target platforms.

However, the new version is breaking compatibility with the previous generation of addons.

What to do if you have incompatible addons

If you absolutely need some addons that are not updated by their developers anymore, you have several choices:

  • You can install Firefox 52 ESR, the version made for enterprises and IT departments that don't want their users' browser to have bleeding edge features, but still wish to receive security update. However, Firefox 55 introduced a new profile structure that can't be downgraded to earlier version. So downgrading to ESR without setting up a new user profile will be impossible - e.g. you will lose your bookmarks, saved passwords and other personal data saved in your Firefox.
  • Or you can try Basillisk or Waterfox, two forks made to reverse the controversial changes made by the Mozilla foundation such as breaking compatibility with extensions not made in the WebExtensions format.

What do you think about this new Firefox?