Controlling the LED backlight brightness on a laptop in Linux used to be a chore, but most window managers automatically configure the brightness buttons on your laptop. However, everything is much more customizable in i3 and it requires a little more configuration.
Controlling the light
First off, we need something that allows us to control the brightness. There’s a perfectly named project called light that does exactly this task! In Fedora, install it via:
$ sudo dnf -y install light
You can query the current brightness:
$ light -G 5.00
On my laptop, 5% is very dim. Now we can increase the brightness using a simple command:
$ light -A 5 $ light -G 9.99
And we can bring it right back down:
$ light -U 5 $ light -G 5.00
Setting up hotkeys
Open your i3 configuration (usually
~/.config/i3/config) and add the hotkey
# Handle backlight. bindsym XF86MonBrightnessUp exec light -A 5 bindsym XF86MonBrightnessDown exec light -U 5
Refresh the i3 configuration with
$mod + shift + r.
Each time you press the brightness up button on your laptop, the brightness level goes up by 5%. The brightness down button lowers it by 5%. This is a good setup for me since I normally only need to adjust it by a few stops depending on ambient light.
However, if your lighting changes drastically from time to time, you can set up a different keybinding for a much more aggressive change:
# Handle backlight. bindsym XF86MonBrightnessUp exec light -A 5 bindsym XF86MonBrightnessDown exec light -U 5 bindsym shift+XF86MonBrightnessUp exec light -A 25 bindsym shift+XF86MonBrightnessDown exec light -U 25
Hold shift and press brightness up or down. Now you are moving up and down by 25% brightness each time. Enjoy! 💡
Photo credit: Ariel on Unsplash