How to easily kill a frozen / locked-up app or window in Ubuntu

Last updated: September 23, 2013

This tutorial shows you how to easily kill / force quit an application or window that freezes or stops responding using xkill & shortcut key.

Xkill is a utility for forcing the X server to close connections to clients. This program is very dangerous, but is useful for aborting programs that have displayed undesired windows on a user’s screen. It works on Ubuntu, Linux Mint, Elementary OS, and other Linux systems.

You can run Xkill from terminal, Alt+F2 run command box or even via a keyboard shortcut. When it runs, your cursor becomes a cross (‘X’). Click on any window will kill it instantly.

Kill frozen window

Warning: Don’t click on Desktop and Panel when running xkill, it will also kill them and break your desktop and you need to restart to restore.

To create a shortcut key for xkill, go to System Settings -> Keyboard -> Shortcut -> Custom shortcuts. Click add to create the shortcut and give a key combination.

Add xkill shortcut

After that, press the key combination and then click on the window you want to kill.



I'm a freelance blogger who started using Ubuntu in 2007 and wishes to share my experiences and some useful tips with Ubuntu beginners and lovers. Please comment to let me know if the tutorial is outdated! And, notify me if you find any typo/grammar/language mistakes. English is not my native language. Contact me via [email protected] Buy me a coffee:

5 responses to How to easily kill a frozen / locked-up app or window in Ubuntu

  1. Hey Li, I droped you an email, hope you got it ?


  2. thanks… it’s an usefull information to me..

  3. thanks for the rescue!

  4. Fantastic info. works like a charm thanks. gets rid of an annoying window when I plug my wife’s iphone that I could never close and had to reboot. I know the real solution was to find why the iphone did that, but I don’t plug it often and didn’t want to waste time figuring it out. this was simple easy and fast.


  5. Brilliant, thanks so much.