Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

At first, I tried to simulate Fn + F5 / F6 in order to control the monitor's brightness, but I totally failed.

So, I started to find out workarounds:

There is a built-in software called gnome-control-center, so I tried to find out the solution from it.

We can see that there is a bar controlling monitor's brightness. Drag to the left for darkening, and vice versa.

I've downloaded the source code for 12.04 [site], but I still couldn't find the code snippet which controls the monitor's brightness.

Could anyone help me? Thanks.

share|improve this question
you can try xbacklight, for example xbacklight -set 80 but typically this means that you have some problem with your drivers. Which driver did you have installed ? – user2485710 May 6 '14 at 17:50
@user2485710 Where can I find the driver name installed by system autimatically? – Kevin Dong May 6 '14 at 17:53
@user2485710 Oh, my graphics driver is NVIDIA 331.20. BTW, the driver provided by NVIDIA works totally fine. I just want to control the brightness from software in the background. – Kevin Dong May 6 '14 at 17:55
I don't have any recent experience with the Nvidia drivers, anyhow the way you are supposed to follow to install proprietary drivers under Ubuntu is to use Software & Updates -> Additional Drivers which is basically the old jockey-gtk . Other methods are likely to be unsupported and you are supposed to know what you are doing as you do it. Wait for someone experienced with Nvidia software. – user2485710 May 6 '14 at 18:05

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.