Screen brightness in Ubuntu 18.04

Solution 1:

I found an answer, but not the best one!

Read this, to change the /etc/X11/xorg.conf file.

I did the solution from that post, and installed the new updates, then xbacklight worked. But still, I couldn't change the brightness from setting. According to this answer, you can increase the screen brightness by 10% by this command:

xbacklight -inc 10

And decrease the brightness by 10% by this command:

xbacklight -dec 10

Then create a keyboard shortcut, for intsance, shift+f9 for command xbacklight -inc 10, or so. Unfortunately, it doesn't let you use fn+f9 shortcut, since it is supposed to have a job itself primitively.

Solution 2:

On Ubuntu 18.04 (with xfce desktop) my brightness problem finally solved.

I opened 'Onboard Settings' under the 'Settings' menu. If your desktop doesn't have one, you can download it from Software Center.

On the 'Onboard Preferences' window, click the Layout menu, then choose the 'Full Keyboard' (Desktop keyboard with edit and function keys). Click here to view the Onboard Settings window

Solution 3:

In case the above suggestion doesn't help you. Here I am suggesting which might help you. I have installed fresh Ubuntu 18.04 LTS and landed at this problem. In case, you have Nvidia Graphics Driver. Please do the following: Edit (or create) inside /usr/share/X11/xorg.conf.d/10-nvidia.conf

Section "OutputClass"
    Identifier "nvidia"
    MatchDriver "nvidia-drm"
    Driver "nvidia"
    Option "AllowEmptyInitialConfiguration"
    Option "RegistryDwords" "EnableBrightnessControl=1;" # Add this if it exists
    ModulePath "/usr/lib/x86_64-linux-gnu/nvidia/xorg"
EndSection

Commands:

sudo vim /usr/share/X11/xorg.conf.d/10-nvidia.conf
Check with the above code.