How To Control Brightness On External Monitor


I have a Dell XPS 9350 connected to a Dell External monitor over USB-C. I am running Wayland and Gnome 42.

As the subject states, looking for a brightness app / extension that can control my External Monitor. I currently have a laptop with an external monitor connected (over USB-C), and the default brightness app only controls the monitor internal display.

What is the easiest way to control the brightness of the external monitor?

I tried the following application, but it did not work for me:

Any assistance would be greatly appreciated. Thanks!

Hi @A4orce84,

I don’t at all know if this is what you’re looking for, if it’ll work, or anything else for that matter, so if it’s not what you’re looking for…:man_shrugging:

It would seem, however, as if brightness-controller is in the AUR:

$ pamac search brightness-controller
brightness-controller-git                                                                                                                                                                                                         2.3.4.r286.ea7434a-2  AUR
Control Brightness of your Primary and Secondary Display in Linux

So it can be installed using:

pamac build brightness-controller-git

Hope this helps!

Yup, I installed it and the application window launches. However, adjusting any of the actual brightness settings does not DO anything on my system.

Have you tried launching it from the terminal and see is there are any errors?


According to you link:

This all works via xrandr, so if you’re using a Wayland session this app, alas, won’t work.

So, it’ll not work for you since you use Wayland.

However, I have found some alternatives:

Screen Dimmer, which is in the AUR:

$ pamac search dimmer
screendimmer                                                                                                                                                                                                                                   0.4.2-1  AUR 
A tray application to dim your monitor brightness.

It can be installed with:

pamac build screendimmer

As well as desktop-dimmer, also in the AUR:

$ pamac search dimmer
desktop-dimmer                                                                                                                                                                                                                                 4.0.4-2  AUR 
Enables darker-than-dark Desktop dimming for your displays.

So, it can be installed using:

pamac build desktop-dimmer

Or dim-screen, also in the AUR:

$ pamac search dimmer
dim-screen                                                                                                                                                                                                                                     1.0-1    AUR 
A screen dimmer bash script designed to work with xss-lock

So, can be installed using:

pamac build dim-screen

However, I don’t use Wayland, so can’t know.


Terminal output:

~  brightness-controller                                                                                                        ✔ 
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.

Try starting it with:

QT_QPA_PLATFORM=wayland brightness-controller

But, as I said, Wayland is not supported, so it might not even probably won’t work.

For me ddcutil works well. It is a command utility but that should not scare a Manjaro user.
ddcutil gives commands to the monitor directly, don’t know if it works through usb-c though.

Try vdu_controls available in the AUR.

I use xrandr. It works, but it is tricky to set with login script. I had to use a sleep 32 command before xrandr in the little script I created.

Here is my sample xrandr command, with VGA-1 being the external monitor. I have the laptop screen pumped up on the gamma in the KDE gamma settings and so to compensate I had to lower the gamma output on the external display. You could start with values of 1 for red, blue and green and experiment from there.

/usr/bin/xrandr --output VGA-1 --gamma .45:.50:.60

xrandr doesn’t work with Wayland, IIRC, so is no use here and won’t work. But see

Perhaps that helps!

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The xrandr method is a work around, and not a perfect one. I hope KDE will SOON offer gamma tweaking to individual monitors on dual monitor setups.