Via shading :

xrandr -q | grep connected xrandr --output eDP-1 --brightness 0.5 (eDP-1 is my monitor)

Via backlight :

sudo vim /sys/class/backlight/intel_backlight/brightness

### in /sys/class/drm you'll find all displays
### /sys/class/drm/card0/card0-eDP-1/enabled check to see if it's active or not.

Via app :

sudo pacman -S light replace the lines of code in the i3wm .config file: bindsym XF86MonBrightnessUp exec light -A 5 # increase screen brightness bindsym XF86MonBrightnessDown exec light -U 5 # decrease screen brightness

link

Via i3bar :

To construct our block, put the following lines to your i3blocks.conf :

[backlight]
command=xbacklight | sed -r 's/.w+$/%/'
label=B
interval=5

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