How to replace Unity with i3 window manager on Ubuntu 12.04

06 Dec 2013 // in: tech // tags: i3, i3wm, window manager, and ubuntu

So you’ve decided that you don’t like Unity and you’d like to replace it. i3 window manager is a popular tiling window manager that is easy to learn and can greatly improve productivity. Once you’ve gotten the hang of all the hotkeys, you’ll find that you rarely need a mouse or touchpad anymore. I personally became much more productive when I installed it, but I had some trouble finding good information on how to completely replace Unity a still retain the default Ubuntu login manager called lightdm.

Installing i3

In order to install the stable version of i3 on Ubuntu, open up your terminal using Ctrl + Alt + T and run the following commands under root (preferably using sudo):

# login to the root shell for one 'echo' command
sudo -i
echo "deb http://debian.sur5r.net/i3/ $(lsb_release -c -s) universe" >> /etc/apt/sources.list
logout
# we've returned to our user account
sudo apt-get update
sudo apt-get --allow-unauthenticated install sur5r-keyring
sudo apt-get update
sudo apt-get install i3

At this point, you’ll be able to use i3 and make sure that it works well on your system. To use i3:

  • Logout of Unity
  • From the login screen, click the circle icon above your user account
  • Select “i3”
  • Login with your password
  • i3 will offer to create a config file. Press enter to create it
  • i3 will ask you to choose a modifier key. Choose the key you’d like by pressing it on the keyboard and then press enter

You’ll find yourself at a black screen. Welcome to i3! Assuming you’re not familiar with the hotkeys, you can use Modifier + D to open the application launcher or Modifier + Enter to open a terminal. To logout of i3, open a terminal and run the command i3-msg exit

Removing Unity

If you’re satisfied with i3, and you’d like to use it along with the login screen lightdm, we’ve got the option of removing Unity and Compiz. To do that, run the following commands:

sudo apt-get autoremove --purge compiz compiz-gnome compiz-plugins-default libcompizconfig0

sudo apt-get autoremove --purge unity unity-common unity-services unity-lens-* unity-scope-* libunity-core-6* libunity-misc4 appmenu-gtk appmenu-gtk3 appmenu-qt* overlay-scrollbar* activity-log-manager-control-center firefox-globalmenu thunderbird-globalmenu
# the following command will disable the desktop (we won't need it with i3!)
gsettings set org.gnome.desktop.background show-desktop-icons false

Configuring lightdm

Since we removed Unity, we need to reconfigure the login manager lightdm to login with i3 by default. This can be accomplished with a few simple steps:

  1. Run the command sudo nano ~/.xinitrc
  2. Type into the file exec i3
  3. Save the file using Ctrl + O
  4. Exit the file using Ctrl + X
  5. Run the command sudo nano /etc/lightdm/lightdm.conf
  6. Change the line with user-session to read user-session=i3
  7. Save the file using Ctrl + O
  8. Exit the file using Ctrl + X
  9. Restart your computer with the command sudo init 6

You’re done! Enjoy your new window manager!

Want to keep going/learn more? Check out my customization guide/cheat sheet

Author: Brent Walther