Update How to maintain compact mode in FireFox


Level 7
Aug 2, 2020
Maintain compact mode for current users and move to about:config preference

Acceptance criteria:
- Compact mode is behind a preference. Enabling the preference will make the “Compact mode” density option appear in the customize UI density picker.
- The string in the picker is updated to “Compact mode (not supported)”
- Current users of compact mode will get the preference automatically enabled
- A SUMO article will describe how users can enable compact mode
Early on in our work defining MR1 we were faced with a decision, design two modes for our Tab experience or focus on one. At that time we made the decision to focus on designing one tab management experience that does the job well.
We heard the feedback loud and clear from the earliest iterations on vertical spacing, which shared concerns we had as a team. Since then we’ve changed and continued to refine how the base experience behaves.
So we’re going to ensure current users can retain compact mode if they already enjoy it. For other users they can find the feature behind a pref; to reveal it as an update in the density picker.
While this feature is not supported, we’ll make a SUMO article available so others can learn how to enable this feature.
For the recommended and supported experience, we encourage you to keep the normal density setting--we’ll be listening to feedback and discussions from the community, and product research as we design future iteration of this experience and other tab experiences.


Level 9
Jan 17, 2014
I honestly love the compact mode/low density of FF and is the main reason why I use as my primary browser now.
If other browsers had this option I would give them a try but so far FF is the only browser I've seen that has it.

I'm a very picky user. I know some browsers have better features than FF and are more up to date but I just hate the interfaces, very big and "blown up" in my eyes atleast. I also dislike completely square tabs or completely rounded tabs like current versions of Chrome. I don't know why I don't like that style design. I just don't lol

I've also got FF modified to where the tabs are the shape of the beta version of chrome. I guess you would say like a triangle almost? The only browser that comes close to allowing this level of customization is Vivaldi and even then it has limitations.


Level 7
Aug 2, 2020
If you follow Firefox web browser news you may have read some time ago that Mozilla planned to remove the browser's compact mode from the customization options. Compact Mode is one of Firefox's three density modes for its main interface; it is the smallest layout option and leaves most room for webpages displayed in the browser. The other two modes, normal, which is the default, and touch, which is for touch-capable devices, display a bigger interface.

Mozilla's original plan was to remove the Compact Mode option from the browser's customize menu. You may access the customize option by selecting Main Menu > Customize. The reason that Mozilla gave for the removal was that the option was "hard to discover" and that it believed that "it got low engagement".

The reasoning did not sit well with Firefox users, many of which were using Compact Mode in the browser. A new bug on Mozilla's bug tracking site reveals Mozilla's plan for Compact Mode in Firefox.



Level 74
Content Creator
Malware Hunter
Aug 17, 2014

Enable Compact density option in customize panel in Firefox 89​

  1. Open Firefox
  2. Visit about: config
  3. Click on Accept the risk and continue button
  4. Search for compact, in the displayed results, toggle browser.compactmode.show pref value to true.
  5. Click on the hamburger menu button and select More Tools > Customize toolbar
  6. At the bottom, click Density and choose ” Compact (not supported)” (the compact option is back and available to select)

    select compact (not supoprted) option

  7. Click Done.
Mozilla is recommending users to keep and use the Normal density option for a supporting experience.