Enable the new Proton Design in Firefox

How to Enable the new Proton Design in Firefox.

Mozilla is about to update the appearance of the Firefox browser in 2021. The UI design, which most Firefox users know as "Photon", will get a visual and feature refresh in Firefox 89.


Firefox is a popular web browser with its own rendering engine, which is very rare in the Chromium-based browser world. Since 2017, Firefox has the Quantum engine which comes with a refined user interface, codenamed "Photon". The browser doesn't include support for XUL-based add-ons any more, so all of the classic add-ons are deprecated and incompatible. Check out Must have add-ons for Firefox Quantum.
Thanks to the changes made to the engine and the UI, the browser is amazingly fast. The user interface of Firefox became more responsive and it also starts up noticeably faster. The engine renders web pages much faster than it ever did in the Gecko era.

The current version of the "Photon" user interface was released with Firefox 57. In 2021, Mozilla is about to refresh it. Reportedly, the new "Proton" UI will look modern, and will also get new features like vertical tabs and tab grouping. Both of these features already implemented in other browsers like Vivaldi and Microsoft Edge.

Mozilla has created a bug collection which allows tracking the changes in the Proton version of the UI. From the bug names it is clear that the following UI elements will be updated.

  • The Firefox address bar and tabs bar.
  • The main Firefox menu.
  • Infobars.
  • Doorhangers.
  • Context Menus.
  • Modal dialogs.

Here are some mockups of how the updated interface will look.

Firefox Proton UI 2021 Image 1Firefox Proton UI 2021 Image 2Firefox Proton UI 2021 Image 3Firefox Proton UI 2021 Image 4Firefox Proton UI 2021 Image 5Firefox Proton UI 2021 Image 6Firefox Proton UI 2021 Image 7

You can enable the new Proton UI in Firefox in about;config, but at the moment of this writing it doesn't do anything even in Nightly. Anyway, the procedure is as follows.

To Enable the new Proton Design in Firefox

  1. Open Mozilla Firefox.
  2. Type about:config in the address bar and press the Enter key.
  3. Click on Accept the Risk and Continue on the Proceed with Caution page.Firefox About Config Accept Risk Proceed With Caution Confirm
  4. Type browser.proton.enabled in the search box.
  5. Double-click on the browser.proton.enabled parameter to set its value to true.Enable The New Proton Design In Firefox
  6. Restart Firefox.

That's it.

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13 thoughts on “Enable the new Proton Design in Firefox

  1. BetterKnower

    Current UI ist Photon, new one is Proton.

    1. Sergey Tkachenko Post author

      Thanks. Changing the text.


      My Google Play does not open or save anything. Including Firefox and Chrome!

  2. Panos

    Weird! I followed all the steps and double checked that the about:config was in fact set in true but I don’t see any new changes.

    1. hypermug

      The redesign hasn’t been finished yet. The above steps opt you in for when the design is ready.

  3. EFI Shell

    Not working (Mozilla Firefox 84).

    1. Sergey Tkachenko Post author

      It is not working in any Firefox version as of right now.

      1. Ed L

        I believe this option is only available in nightly/beta build at this time.

        1. Sergey Tkachenko Post author

          You are right. Anyway, it does nothing in my Nightly.

  4. Siddharth

    I tried to give Firefox a chance but it is complete garbage
    i couldn’t install my favorite extensions that are available for chromium
    and the biggest drawback was…
    i know that could be done via an extension
    but this doesn’t enables us to get suggestions in address bar
    and why would anyone go through this much pain
    also their support team is garbage

    1. hypermug

      There isn’t even a “support team”. It’s just volunteers

  5. Miguel

    Works now in Firefox Nighty 87.0a1 (26 january)

    1. Nils

      Works for me as well. Mac users might need to add the following properties manually to about:config.
      browser.proton.appmenu.enabled true
      browser.proton.tabs.enabled true


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