How to restart X Window Server from command line?

Question

How can I restart X Window Server from the command line?

I'd really like to be able to restart my GUI without having to do a full system reboot.

Answer 1

NOTE: This will forcefully quit all graphical programs, you'll lose any unsaved work, and you'll be logged out. Non-graphical programs will not be affected.

TL;DR: on systems with systemd (Ubuntu 15.04 and newer)

sudo systemctl restart display-manager

This will restart the appropriate display manager service (lightdm till 17.04, gdm3 after, sddm in Kubuntu, etc.). You can replace display-manager with lightdm, gdm3, sddm, etc. if needed, but this should be enough.

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For other Ubuntu versions, first find which display manager your ubuntu is having with following command:

cat /etc/X11/default-display-manager

Than depending on what display manager, you can use one of the following commands:

• Default Ubuntu (with LightDM)

  sudo systemctl restart lightdm  
  

• Gnome (with GDM)

  sudo systemctl restart gdm
  

• KDE (with KDM)

  sudo systemctl restart kdm
  

  Note: From 12.10 to 15.04, Kubuntu also uses LightDM.

• For MDM (e.g. for Mint Cinnamon)

  sudo systemctl restart mdm
  

Answer 2

For 11.04 and earlier:

sudo service gdm restart

For 11.10 and later:

sudo service lightdm restart

Answer 3

Found out that you can do sudo pkill X

and it seems to work for me!

Answer 4

You can try pressing Ctrl+Alt+Backspace to restart X.

Answer 5

Newest version of Ubuntu as of 24 Oct, 2012.

1. Open Dash Home
2. Search for keyboard layout
3. Click Options
4. Expand tab labelled "Key sequence to kill the X server"
5. Enable it and Close.

Command Line:

sudo restart lightdm

Answer 6

Since ubuntu 9.04 Ctrl+Alt+Backspace is disabled, however you can now type Alt gr + Print Screen + K.

http://www.sudo-juice.com/ubuntu-11-10-restart-x-shortcut/

Answer 7

For KDE:

sudo systemctl restart sddm.service