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's backlight property. When called without arguments, it prints the current brightness level as a percentage. The -set, -inc, and -dec options modify the brightness.The -time and -steps parameters enable smooth fade transitions, spreading the brightness change over the specified duration.
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; does not work with Wayland. Requires the RandR backlight property to be exposed by the display driver. Many modern laptops and proprietary drivers (e.g., NVIDIA) do not expose this property. Use brightnessctl or light as more reliable alternatives that work via sysfs.
SEE ALSO
brightnessctl(1), light(1), xrandr(1)
