Check Which Display Manager are Using on Linux

On Linux systems, the display manager plays important role in providing the graphical login screen and starting the desktop session. It handles user authentication and launches the chosen desktop environment after login. Common display managers include GNOME Display Manager (GDM), Simple Desktop Display Manager (SDDM), LightDM, LXDM, and XDM. When troubleshooting login issues or identifying system configuration, determining the active display manager can be useful. This tutorial shows how to check which display manager are using on Linux.

On most modern Linux distributions, the active display manager can be identified through the display-manager service managed by systemd. Run the following command:

systemctl status display-manager

Example output:

gdm.service - GNOME Display Manager
     Loaded: loaded (/lib/systemd/system/gdm.service; static)
     Active: active (running) since Wed 2026-06-03 07:33:47 EEST; 6h ago
    Process: 1067 ExecStartPre=/usr/share/gdm/generate-config (code=exited, status=0/SUCCESS)
   Main PID: 1167 (gdm3)
      Tasks: 3 (limit: 37807)
     Memory: 6.7M
        CPU: 145ms
     CGroup: /system.slice/gdm.service
             └─1167 /usr/sbin/gdm3

From this output, the service name and main process indicate the active display manager (in this case, GDM3).

On Linux distributions without systemd, the active display manager can be identified using process inspection tools such as ps. This involves filtering running processes for known display manager binaries:

ps -eo comm | grep -E '^(gdm|gdm3|sddm|lightdm|lxdm|xdm)$'

Example output:

gdm3