The YouTube downloader for Kubuntu is a handy little program that does exactly what it says it does with a couple of extras. The basis of the program is on the command line though but if you want a GUI front end to it then the YouTube-DL GUI does the trick just fine.
This installation will be in two parts, the first for youtube-dl which is the commandline portion that does most of the work and the second to install YouTube-DL GUI to make it look good. Warning, you can install youtube-dl straight from the 18.04 repository but you will find in many cases it doesn’t work as things have changed since it was packaged. You want the updated version.
To install youtube-dl in Kubuntu 18.04 open up Konsole and type,
sudo wget https://yt-dl.org/latest/youtube-dl -O /usr/local/bin/youtube-dl
This will download youtube-dl using sudo permissions (you may need to enter your password) and place it in /usr/local/bin/. Afterwards you will need to give it the correct permissions with,
sudo chmod a+x /usr/local/bin/youtube-dl
The hash command makes sure that when you run youtube-dl it runs the one at /usr/local/bin/ and forgets all the others. Afterwards we need to make sure youtube-dl is up to date and we to so with the command,
sudo youtube-dl -U
Now we are ready to install the GUI.
To install YouTube-DL GUI you will need to add the repository first. You can just download the package from the repo but this way it will keep up to date and you wont have to manually add the twodict package as well. Again, open up Konsole and type,
sudo add-apt-repository ppa:nilarimogard/webupd8
You will probably have to press enter again and then the repository will be added and auto updated. Afterwards type,
sudo apt install youtube-dlg
And YouTube-DL GUI will be installed. You will be able to find it in the main menu under Applications/Internet or by clicking on the main menu button and searching for YouTube.
Tips and Tricks
I can’t say that I have used the YouTube-DL GUI much yet as I usually just use the command line. The basic usage is just to type youtube-dl and then the YouTube URL you want to download. It defaults to downloading straight to my home folder which is fine with me.
youtube-dl <enter URL>
The only other usage I really use is to do the same thing but only download the audio file of the video. To do this you simply add an -x switch into the command like this.
youtube-dl -x <enter URL>