xbacklight
Adjust screen backlight brightness
TLDR
Get current brightness
$ xbacklight
Set brightness$ xbacklight -set [40]
Increase brightness$ xbacklight -inc [25]
Decrease brightness$ xbacklight -dec [75]
Set with fade effect$ xbacklight -set [100] -time [60000] -steps [60]
SYNOPSIS
xbacklight [OPTIONS]
DESCRIPTION
xbacklight adjusts backlight brightness using the X RandR extension. It provides a simple interface for getting and setting screen brightness on laptops.
The time and steps parameters enable smooth fade transitions when changing brightness.
PARAMETERS
-set PERCENT
Set brightness to percentage-inc PERCENT
Increase brightness by percentage-dec PERCENT
Decrease brightness by percentage-time MS
Fade duration in milliseconds-steps N
Number of steps for fade
CAVEATS
X11 only. Requires RandR backlight support. May not work on all hardware or with proprietary drivers. Alternative tools like brightnessctl may work better.
SEE ALSO
brightnessctl(1), light(1), xrandr(1)