How to Remove the GUI from your Raspberry Pi

I was getting prepared to start another headless Raspberry Pi project (an IoT gateway) and reached for my old standby command line operating system, Minibian. I grabbed the latest version, copied the image to the memory card, and started setting things up. I ran into a problem when I tried to get the RaLink RT5370-based USB WiFi Adapter working - the kernel seemed to recognize the device, but I just couldn't get it working. After digging through the system logs it became apparent the firmware required by the adapter was not present in Minibian (Only later did I realize that I may have just needed to install a package to get the required firmware). After trying to get the WiFi adapter to work for a few hours, I gave up and switched to Raspbian. I was then able to get everything working (including the WiFi adapter), but was left with a GUI and it's associated bloat that I didn't really need, so I set about seeing what packages could be removed and still leave me with a fully functioning command-line based system.
 
Initially, I just did a search on the web and found a few different posts and conversations that dealt with removing the GUI and combined them to get things slimmed down quit a bit. After that, I started listing the installed packages and removing the ones that looked like they would not be needed. (It was at this point I noticed the firmware-ralink package that I could have probably installed on Minibian to get the WiFi adapter working there – maybe next time).
 
My first stop was a conversation on raspberrypi.stackexchange.com where it was suggested that you could rip out the X window system by the roots by simply removing ''libx11-.*''. That did remove a lot of packages from the system! Other blog posts like this one at Richard's Ramblings added to the list of packages to remove.
 
Finally, I used the dpkg --get-selections | grep -v deinstall command (thanks askubunut.com!) to list all the remaining packages on the Raspberry Pi and removed all the ones that look like I could do without. There were a few times when I removed too much and had to re-install a package or two, but eventually boiled it down to the following commands to convert a normal GUI Raspbian installation to a lean command-line only version (Be sure you don't have any important files or configuration on your system before doing this, and don't blame me if your mission critical Raspberry Pi application gets lost in the process!).  
A word of caution: One of the uninstalled packages took the /etc/network/interfaces file with it, so before stripping all these packages, you should make a copy somewhere else on the device and then restore it before rebooting your system, or you will have no networking available after rebooting!
 

sudo apt-get remove --auto-remove --purge libx11-.*
sudo apt-get remove --purge raspberrypi-artwork triggerhappy shared-mime-info gcc-4\.[0-7].*
sudo apt-get remove --purge gdb gdbserver penguinspuzzle samba-common omxplayer
sudo apt-get remove --purge alsa-.* build-essential gstreamer1.0-.* lxde-icon-theme
sudo apt-get remove --purge desktop-file-utils gnome-themes-standard-data menu menu-xdg
sudo apt-get autoremove

After all was said and done, I was able to reduce the size of the file system from 2.5GB down to just 800MB. Along with the size savings, there are also fewer programs running and fewer packages that need updating. Not to mention having less software on the system creates a smaller attack area for hackers to leverage.
 
So if you find that you need to remove the GUI from your Pi, hopefully this information will help you with your cleaning task. And of course, if you need something even smaller, there's always Minibian for a really stripped-down configuration.