Firefox Scrollbars - too thin!

Firefox scrollbars - desktop PC - are, from my point of view, too thin (me, 50+ years old). I cannot exactly recall what version it was, it started to annoy me. I used an extension (Custom Scrollbars - you can find it as Firefox add-on) in the meantime, but this does not work anymore on my Ubuntu MATE 21.10 PC with Firefox 98.0.1.

Searched for a possible solution and found this topic (Tweaking your Scrollbar Settings). Unfortunately, the css based on the recommendations in the topic did change the scrollbars in some apps - e.g. Caja, Eclipse, etc. - but NOT in Firefox!

But, further searching led me to this:

  • open a new tab in Firefox
  • in the address bar type
  • click Accept the Risk and Continue
  • in the Search preference name field type

A list of preferences starting with widget.non will be shown.

What I've changed:
widget.non-native-theme.gtk.scrollbar.thumb-size => set to 1.50
widget.non-native-theme.scrollbar.size => set to 16
widget.non-native-theme.scrollbar.size.override => set to 16

You may also want to consider following preference:
widget.non-native-theme.gtk.scrollbar.allow-buttons (I set it to true)

Hope this helps :slight_smile:

By the way, the "Custom Scrollbars" add-on, is still in use here - it still allows customising the color of the scrollbar :innocent:


I agree, I am 66, so I set my screen resolution to 136x768. That makes everything larger.

Also under system>Control Center>Look and Feel>MATE Tweak>Windows>Windows manager what is your setting? I have mine set to Marco (no compositor) but you might want to set your to Marco (Adaptive compositor). Using a compositor can affect the size of the scroll bar.

"If you have trouble resizing windows with the mouse, because the resizing borders are too thin, option "Marco (Adaptive compositor)" can help."

Options "Marco (No compositor)" and "Marco (Compton GPU compositor)" give you extremely thin window resizing borders that are hard to hit with the mouse.

Many users do not know or do not want to use the "Alt+mouse" window resizing method. Besides, if you are using a laptop touchpad or a remote desktop session, resizing windows with their borders may be the only comfortable option.

I have collected detailed information about window resizing issues here:


I use Control Center - Look and Feel - MATE Tweak - Windows - Window manager => Marco (adaptive compositor).

1. Marco (adaptive compositor)

  • scrollbars in all windows have a normal width, except for Firefox, Vivaldi, Brave and Edge and Thunderbird
  • resizing of windows works good - resizing borders are ok (quite large) - see image below

Set Marco (no compositor) and restarted PC

2. Marco (no compositor)

  • scrollbars in all windows have a normal width, except for Firefox, Vivaldi, Brave and Edge and Thunderbird
  • resizing of windows works good - resizing borders are ok (quite large) - see image below

This means, at least for my PC:
- Marco (adaptive compositor) or Marco (no compositor) have no influence on the scrollbars

This is a screenshot done via ALT+PrtScr while Marco (no compositor):

  • you can see that the screenshot is larger that then window itself containing the "resizing borders"
  • the same in case of Marco (adaptive compositor)

Before adapting the settings via "about:config" in Firefox, I tried the solution recommended here: scrollbar-width - CSS: Cascading Style Sheets | MDN, by setting the scrollbar-width: auto; in ~/.config/gtk-3.0/gtk.css (log out and log in again or PC restart) but with no success.

1 Like

Superb info in the OP - sincere thanks @Radax05 !!

My FF did not have the line
But I did the others & it does make the scrollbars WAY more user friendly.

My 27" display is also set to 1360 x 768 as with Jymm and that is fine for most everything I use - but FF was an annoying exception, now fixed.

Aside of that I must add that my only usage anymore for FF itself is for a single video source which was difficult when scrolling info there until now.

My main, 'daily driver' browser is Basilisk, 2nd to that is Librewolf, I also use an older version of the non-Linux Mypal every day - ungoogled Chromium when I am forced to - so FF comes in around 5th place for me.

Once it became chrome-ized I really lost interest in using it.

Basilisk uses the original add-ons and with the addition of the Classic Addons Archive as well as Classic Theme restorer it brought browser sanity back for me - rather than the lobotomized & mostly un-customizable baloney that FF itself has become.

1 Like

You saved my life. I'm 67 and I cannot recognize a priest in the snow :slight_smile:
Thank you very much

I've registered here just to put LIKE to your story and thank you. You helped a lot. Let your dreams come true.

1 Like


I am 80 years young now, and even with 20/20 far vision,
seeing things up close no longer works, as my eye muscles refuse to focus up close, then look out there....

thanks for this, I am using Linux Mint LM21.1 Cinnamon today, but Firefox is Firefox, and this is relevent today.



already posted, but added my LIKE to this.

Welcome @John_Craig to the community!

True. Will need to use this to optimize for 14" display.

But you can wait ~2 years until epigenetic reprogramming of vision with OSK Yamanaka factors will be available for humans.