How to Uninstall or Remove Packages in Ubuntu

List installed packages

dpkg --list

apt list --installed

Show the 20 biggest packages:

dpkg-query -Wf '${Installed-Size}\t${Package}\n' | sort -n | tail -n 20

remove deletes the program but keeps its configuration files.

sudo apt remove package-name

Example:

sudo apt remove firefox

purge deletes the program and its configuration files.

sudo apt purge package-name

sudo apt purge firefox

After a removal, some packages that were installed only as dependencies are no longer needed:

sudo apt autoremove

Remove them and their configuration files:

sudo apt autoremove --purge

Read the list before you confirm.

apt-get works the same way:

sudo apt-get remove firefox

sudo apt-get purge firefox

List the snaps:

snap list

Remove one:

sudo snap remove package-name

Note: On current Ubuntu versions apt install firefox installs a snap, so use snap remove firefox to remove it.

First see the kernel you use:

uname -r

List the installed kernels:

dpkg --list | grep linux-image

Remove an old one (never the one you run):

sudo apt remove --purge linux-image-5.15.0-91-generic

sudo apt autoremove also removes old kernels in most cases, and Ubuntu keeps the last two.

sudo apt clean