If you’re using a laptop, you or may not have actual physical controls.
Adjust brightness on computer screen full#
Simply you could say the brightness value 0.8 means 80% of the full display brightness, or 0.6 means 60%. Or if it's a Display Port, use xrandr -output DP1 -brightness 0.6.If the monitor is connected to a VGA port, then xrandr -output VGA1 -brightness 0.8.If the monitor is connected to a HDMI port then use xrandr -output HDMI1 -brightness 0.7.For the internal display of a laptop, which is connected via LVDS, use xrandr -output LVDS1 -brightness 0.8.etc.īut that might not be enough, to lower the brightness even below the monitor vendor's lowest level, you've to use the xrandr Linux command line tool. If it's a desktop or an external monitor is connected to a laptop with a VGA or HDMI cable, then the above method's won't work.Įvery external monitor has some kind of remote or dedicated switch to control the brightness, contrast, color saturation etc. Using Xrandr command to adjust Linux screen brightness echo '3' > /sys/class/backlight/acpi_video0/brightness # set brightness level 3 3. The same thing as also applicable for the acpi_video0 directory, you can adjust linux screen brightness from there, only if it's supported. 200 > /sys/class/backlight/intel_backlight/brightnessĪnd of course you need root privilege to manipulate that file. The brightness file actually controls the amount of backligh, you can change it like below. The value inside the max_brightness file is the maximum brightness you can assign to the display, and it's not possible to change. ls /sys/class/backlight/intel_backlight/Īs you might have guessed, all the options there are quite straight forward to understand. So, first you might want to get an overview, what's actually inside that directories, use the ls command. In my case it's intel_backlight and acpi_video0, however it's not possible to change brightness with the second interface, in mu case. And there might be more than one controller interface. The display backlight related sysfs parameters are under the /sys/class/backlight/ directory. If the brightness adjustment key's are not working even after adding the kernel parameters, then you could try to directly manipulate the sysfs interface. Xbacklight -set 20 # set brightness to 20% 2.
Adjust brightness on computer screen install#
If it's not installed, then install it with apt, sudo apt-get install xbacklight, and then run the command like below.Įnjoy free shipping and One-Day delivery, cancel any time. After rebooting if the brightness adjustment hotkeys are working then you can set a laptop's brightness with the xbacklight command. You might have to experiment with other options like native and none . The acpi_backlight kernel parameter options are not just limited to vendor, and it's guaranteed to work. Save and exit the text editor and then reboot the laptop.Add a few words there, acpi_backlight=vendor all inside the double quote.Find the line staring with GRUB_CMDLINE_LINUX_DEFAULT=, most probably there will be the word quiet also.First open up the /etc/default/grub file with your favorite text editor as root.If the laptop's default brightness adjustment keys are not working, then add a boot time linux kernel parameter and try again. But here we'll focus on the command line tools. There's many GUI tool like XFCE Power Manager, to adjust the brightness. Each method usability is depending on the hardware platform you're using like a laptop or desktop. Here we'll discus about few different method to control brightness the same.