Adjusting the screen brightness with Xbacklight

Increase and decrease brightness in Ubuntu

xbacklight is a small tool that allows adjust the brightness of our screen through the console using command:

xbacklight -set [porcentaje-brillo]

If we wish for example change screen brightness from one hundred to eighty percent we just have to execute:

xbacklight -set 80


We can also increase and decrease the percentage of brightness without worrying about the exact percentage in which it is. Suppose for example that we want to increase the current brightness of the screen by ten percent, for this we use the option

-inc:xbacklight -inc 10

And to decrease, the option

-dec:xbacklight -dec 10

This is extremely interesting if we want to create keyboard shortcuts that allow us increase and decrease the screen brightness level in order not to have to enter the command in the terminal every time we want to make adjustments.


Xbacklight can be easily installed from the official Ubuntu repositories by running on the console:

sudo apt-get install xbacklight

Increase and decrease the brightness of my laptop

Increase or decrease the brightness on a laptop at present it is very simple. But if you have this doubt, it is probably because the next point, in which I will talk about how to do it with the keyboard, does not work in your case. In the next point I will explain everything necessary for you to do it as it should be but, if for whatever reason it is not possible in any way, we can always do it from the options designed for it.

How to do it will be different depending on the graphical environment that we are using. In the version of GNOME that Ubuntu uses, all you have to do is follow these steps:

  1. We click on the system tray. It is the group of icons that appears at the top right, where we see the volume and the network icon.
  2. We move the slider or slider It has the icon of a sun with half in white and half in black. Sliding to the left we will lower the brightness, while sliding to the right we will increase it.

Increase or decrease the brightness in Ubuntu 19.04

In other distributions like Kubuntu, it is usually in the same system tray, with the difference that it will be in the lower right part. If the battery icon does not appear, it will be because we have removed it from the settings. In the unlikely case that an operating system does not allow it from the system tray, the most normal thing is that there is an option in the Settings / Configuration of the operating system app.

Related article:
Check the temperature of your computer with the command 'sensors'

Increase or decrease the brightness with the keyboard

Today's laptops come with different keyboards than they used decades ago. Long ago, keyboards were simpler and didn't include keyboards. Fn or Function keys, being only the F1, F2, F3, etc that are similar, but not exactly the same. Each brand uses different keys to perform the same action, but today we can raise and lower the volume from the keyboard, turn off the mouse, switch between monitors or, also, raise and lower the brightness. And this is how it has been designed and that is how it should be.

Keys to increase and decrease brightness on Acer

We have two options:

  1. Works directly, of fabric. In this case, pressing on what are usually two suns, one filled and the other empty, will increase or decrease the brightness. The one on the left will lower it and the one on the right will raise it.
  2. Does not work directly. In this case there are two more options: the first is that we cannot do it with the keyboard and the second is that we have to press the Fn key before pressing the brightness increase / decrease keys.

We will rarely stumble upon the second case. Computers already arrive with function keys activated by default. If not, you have to access the BIOS (usually F2 or Fn + F2 when turning on the computer), look for “Function Keys” and check that it says “Enabled” (Activated). If it is not, we activate it and exit saving the changes.

Alternatively create our own keyboard shortcut, but this will not be available in Ubuntu. Yes, we can do it in other more customizable operating systems such as Kubuntu and we can create a customized global shortcut by looking in "global" Preferences to access Shortcuts / Global keyboard shortcuts / Power management. On the right, the options "Increase screen brightness" and "Decrease screen brightness" will appear. We just have to click on one, mark "Custom" and indicate a new keyboard shortcut after clicking "None".

Create custom global shortcut in Kubuntu

Do you already know how to increase and decrease the brightness of your Ubuntu PC?

12 comments, leave yours

Leave a Comment

Your email address will not be published. Required fields are marked with *



  1. Responsible for the data: Miguel Ángel Gatón
  2. Purpose of the data: Control SPAM, comment management.
  3. Legitimation: Your consent
  4. Communication of the data: The data will not be communicated to third parties except by legal obligation.
  5. Data storage: Database hosted by Occentus Networks (EU)
  6. Rights: At any time you can limit, recover and delete your information.

  1.   Germaine said

    As a collaboration I leave here some steps that worked for me to modify the brightness of my laptop from the software and use all the assigned keys (Fn), I use a Samsung RV408 with Intel and KDE:

    In the terminal:

    sudo kate / etc / default / grub

    Locate the lines and modify or add them:

    acpi_osi = Linux
    acpi_backlight = vendor
    GRUB_CMDLINE_LINUX_DEFAULT = "quiet splash acpi_osi = Linux acpi_backlight = vendor"

    Save and close Kate.

    In the terminal:

    sudo update-grub


    In addition, Samsung is recommended to install Samsung Tools:

    sudo add-apt-repository ppa: voria / ppa

    sudo apt-get update && sudo apt-get upgrade

    sudo apt-get install samsung-tools

    sudo apt-get install samsung-backlight

    sudo reboot

  2.   Rafael Barron said

    He does not pay me any attention. Could it be because I have the nvidia driver installed? This is more convenient than making the settings from nvidia's own GUI of course.

  3.   Andrew Cordova said

    Fantastic! Thanks you saved me I have a Toshiba P850 with Ubuntu 12.10 and could not handle the brightness with the normal buttons. Thanks a lot.

  4.   German Alberto Ferrari said

    Thank you very much, it works perfectly on Acer Aspire 7720Z with Ubuntu 12.04.


  5.   Ale said

    What I was looking for. Thanks a lot!

  6.   Ramon Nieto said

    It gives me this message: No outputs have backlight property

  7.   Alexander said

    Hello, I can't make the Fn key work, and, less manage the brightness, the xbacklight or case, I tried modifying the grub and neither, I have the Lubunto 15.04 and my machine is a Notebook Hp pavillion dv 6000 AMD Turion 64 × 2 .. someone suggests something??

  8.   unknown channel said

    Hello. I just installed it on PC with command: sudo aptitude install xbacklight.
    But when executing it, eg: xbacklight -set 80
    It throws me this: "No outputs have backlight property."
    What is it due to?

    I have been using the command eg: xgamma -gamma 0.600. But, although it decreases the brightness, it is not perfect, because various objects on the desktop and on the webs (ex: banners) remain bright.

  9.   Lucas Alexander Ramela said


  10.   giovanicoca said

    Simple, educational, easy to use….

  11.   Sneider Gaviria said

    It worked perfectly for me, thank you very much, you just saved my eyes, I have been looking for how to do it for 1 year, infinite thanks.

  12.   Wen said

    It doesn't work on a desktop pc with an old i7 7700k and integrated gpu