Youtube-dl by far is the greatest tool to download Youtube videos, not to mention majority of Youtube downloader applications make use of it as their core engine.
Youtube-dl is available in official Ubuntu repository. You simply can install it. However, there is a problem with the official repository. The package is not getting updated as frequent as Youtube updates its anti-download security system, even though Youtube-dl developers release updates very frequent. In such case, even if you attempt to update Youtube-dl with
-U switch, you will get following error,
It looks like you installed youtube-dl with a package manager, pip, setup.py or a tarball. Please use that to update.
To resolve the issue, I did Google search and came across with below solution which indeed is piece of cake. You just required to run these commands.
sudo wget https://yt-dl.org/downloads/latest/youtube-dl -O /usr/local/bin/youtube-dl sudo chmod a+x /usr/local/bin/youtube-dl
Now your Youtube-dl should work properly. Keep calm and enjoy downloading Youtube videos.