Brightness won't change

[Zircon34]

Which DE? Edit, if its i3wm:

Problem with backlight keys

Or you may try this if the above doesnt work, bindsym XF86MonBrightnessUp exec xbacklight -inc 10 bindsym XF86MonBrightnessDown exec xbacklight -dec 10 and if needed install xbacklight sudo pacman -S xorg-xbacklight