How to set a permanent system brightness value for Ubuntu Linux

By | July 21, 2016

Reducing the brightness of your PC is a very good thing to do for several reasons, among which are the reduction of power (battery) consumption and the optical effects it can have on the eyes of a regular PC user. By default I set the brightness of all my systems to the lowest value possible (0). If you’re unlike me I know you’d prefer a brightness level between the maximum and minimum value, then this post is for you. So let’s get started.

After you set the brightness to your desired level open up a terminal and check what the brightness is set to that value by typing:

cat /sys/class/backlight/acpi_video0/brightness

Take the value shown from that command and

sudo gedit /etc/rc.local

In the file right above exit 0 add

echo your_value_here > /sys/class/backlight/acpi_video0/brightness

And then save the file.

This would permanently set the brightness to your value as rc.local is executed at each reboot.

If you don’t have the /sys/class/backlight/acpi_video0/brightness file, this would not be possible.

Using the GUI:

STEP 1. Go to SETTINGS>>BRIGHTNESS, and you would see a slider to adjust the brightness of your system to your desired value.


STEP 2. Then go to /sys/class/backlight/acpi_video0/ using the nautilus file explorer. Open the brightness file in a text editor, and copy the value of the brightness shown (mine is 0 because that’s what I set it to in the brightness setting earlier).


STEP 3. Go to /etc directory using the nautilus file explorer. Locate and open in a text editor the rc.local file.


STEP 4. In the file right above exit 0 add;

echo your_value_here > /sys/class/backlight/acpi_video0/brightness

and then save the file and reboot.


Happy Linux’NG!


I agree to have my personal information transfered to MailChimp ( more information )

Join over 10,000 visitors to receive Open Source tips, trick, news, tutorials, programming and more.

We hate spam. Your email address will not be sold or shared with anyone else.

MUST READ  Open Source PowerShell: Microsoft Loves Linux?

Tell us what you think

This site uses Akismet to reduce spam. Learn how your comment data is processed.