The display manager is the graphical interface you use to enter your credentials when logging in to your system. Knowing how to change the display manager is helpful when you want to customize your desktop, as the login screen is a prime aspect of a Linux desktop.

Although GDM, the default display manager on Ubuntu, works well out of the box, you can quickly switch between LightDM and GDM if you want.

Switch Between LightDM and GDM on Ubuntu

The command you'll be using to change the display manager is dpkg-reconfigure. As the name suggests, it reconfigures the packages after they've been installed on your system.

Note that the following command assumes you've at least two display managers installed on your computer. If you only have GDM installed, the command will exit without any output.

        sudo dpkg-reconfigure gdm3
    

You'll see a ncurses-based interactive interface detailing some basics of display managers and how you can use multiple display managers on Linux. Highlight Ok and press Enter to continue.

The system will display a list of all the currently installed display managers on the Configuring gdm3 screen. Here, you have to highlight and select the display manager you want to use. Select lightdm and hit Enter.

switch between gdm and lightdm

Reboot your machine for the changes to take effect.

Note that the process is more or less the same for changing display managers on other Debian-based distributions, including Kali Linux. All you have to do is install and choose a different display manager on the GDM configuration screen.

If you want to disable LightDM and switch back to GDM, run the following command again:

        sudo dpkg-reconfigure gdm3
    

Then, follow the same steps as above to switch back to GDM.

Changing Display Managers and Login Screens on Linux

Login screen customization is a rudimentary step in personalizing your Linux desktop. There are several Linux display managers to choose from. GDM, LightDM, and SDDM are some of the most prominent ones.

When it comes to GUI and desktops, Linux has a lot of terminologies that may seem similar to a beginner's eye. Display managers, desktop environments, display servers, and window managers—although they might look and sound the same, each of them is different than others in more ways than one.