Ade Malsasa Akbar contact
Senior author, Open Source enthusiast.
Thursday, May 28, 2015 at 23:41

Before, we introduced you Redshift GUI to reduce your screen brightness. Reducing screen brightness may save your eyes and may prolong your laptop battery duration. But you need to install something if you want to do that. What if you want to reduce brightness without installing any program? Use built-in xrandr command.

Reducing into Half

xrandr --output LVDS1 --brightness 0.5

Reduce into Very Low

xrandr --output LVDS1 --brightness 0.1

Back To Normal

xrandr --output LVDS1 --brightness 1 


Double Normal

xrandr --output LVDS1 --brightness 2 
CAUTION: number above one is too bright. It may hurt your eyes.

Knowing Your Output

If the command above fails, probably your output screen LVDS1 is incorrect. LVDS1 is used in laptop. You should know your output screen whether it is LVDS1 or else. Use this command
xrandr -q

See the output. Look for the connected line. Ignore the disconnected lines. In this example, my correct output is LVDS1. In other hand, DP1, HDMI1, VGA1, and VIRTUAL1 are not my output. See picture above.