How to Reduce External Monitor Brightness in Ubuntu 21.04 [ Solved ]

Prior to Ubuntu 21.04 update, we could easily reduce the brightness of an external monitor using commands like xrandr or using the brightness-controller app. However, the new Ubuntu 21.04 switched to Wayland, resulting in xrandr and brightness-controller app non-functional.

I did some research on how to reduce external brightness in Wayland and the many ‘solutions’ and suggestions online seem not to work on my laptop. The brightness of my monitor even at its lowest setting is a bit too bright for my eyes. So I had to find a way.

Just Disable Wayland and switch back to Xorg. This lazy fix is for people who jusy want an easy and quick way to get back the functionality and not tinker with a lot of commands to make it work with wayland. Just follow the below commands.

How to disable Wayland in Ubuntu 21.04

  • Open a Terminal ( Ctrl + Alt + T )
  • Enter this command sudo gedit /etc/gdm3/custom.conf
  • Find the line #WaylandEnable=false in the configuration file
  • Remove the # from the above line – it should now read WaylandEnable=false.
  • Save the file
  • Reboot your system

After the reboot, your Ubuntu 21.04 will reboot with Xorg. The Xrandr command and brightness-controller app will now work as it used to be on earlier Ubuntu versions.

If you haven’t tried xrandr or brightness controller app yet, check here to know more on how to use those to reduce external monitor brightness.

external brightness ubuntu

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