brightnessctl

List devices with changeable brightness

$ brightnessctl -l

$ brightnessctl get

$ brightnessctl get -d '[device_name]'

$ brightnessctl set [50]%

$ brightnessctl set +[10]%

$ brightnessctl set [10]%-

brightnessctl [options] command [arguments]

brightnessctl reads and controls device brightness on Linux systems. It supports display backlights, keyboard backlights, and other brightness-controllable devices through the sysfs interface.
The tool can adjust brightness using absolute values or percentages, with support for increment and decrement operations.

-d, --device name

Specify device (supports wildcards)

Device class (backlight, leds)

Save state before change

Restore saved state

Suppress output

list (or -l)

List all devices with controllable brightness

Get current brightness value

Set brightness to a value or percentage

Get maximum brightness value

Requires appropriate permissions (often the video group membership). Not all devices support fine-grained brightness control. Minimum brightness may not be zero.

xbacklight(1), light(1), backlight_control(1)