What are instructions on how to download videos from YouTube?

Notice: Terms of Service Violation

Please be aware that by following any of the answers below, you will be violating YouTube's Terms of Service (TOS). In particular, from Section 5.B.:

Content is provided to you AS IS. You may access Content for your information and personal use solely as intended through the provided functionality of the Service and as permitted under these Terms of Service. You shall not download any Content unless you see a “download” or similar link displayed by YouTube on the Service for that Content. You shall not copy, reproduce, distribute, transmit, broadcast, display, sell, license, or otherwise exploit any Content for any other purposes without the prior written consent of YouTube or the respective licensors of the Content. YouTube and its licensors reserve all rights not expressly granted in and to the Service and the Content.

Solution 1:

youtube-dl

Installation from official site:

sudo curl -L https://yt-dl.org/downloads/latest/youtube-dl -o /usr/local/bin/youtube-dl
sudo chmod a+rx /usr/local/bin/youtube-dl

It's also on Ubuntu repos but you will often need to keep it up-to-date with sudo youtube-dl -U

Installation and ugrade from pip (/):

sudo -H pip install --upgrade youtube-dl

Usage:

youtube-dl YouTube-(or-other-website)-video-link

So it will download the video.

You can also take a look at this for very in-depth documentation on how to use it.

Solution 2:

youtube-dl is a great tool for downloading YouTube videos. Install with:

sudo curl -L https://yt-dl.org/downloads/latest/youtube-dl -o /usr/local/bin/youtube-dl
sudo chmod a+rx /usr/local/bin/youtube-dl

Or with pip (python3-pip):

sudo -H pip install --upgrade youtube-dl

Or from Ubuntu's repo (older version)

sudo apt-get install youtube-dl

then use it this way:

youtube-dl [VIDEO_LINK]

For learning more about advance options, run

man youtube-dl

Or check out the documentation.

Original answer

For Firefox users:

You can install the Video DownloadHelper addon in Firefox and download any embedded object, including YouTube videos.

Solution 3:

Minitube

Minitube is a YouTube desktop application. With it you can watch YouTube videos in a new way: you type a keyword, Minitube gives you an endless video stream. Minitube is not about cloning the original YouTube web interface, it aims to create a new TV-like experience.

It does not require Flash Player. From this application you can watch and download videos.

Solution 4:

Browser addon:
http://www.clipconverter.cc/addon/

Other sites that can be used:

http://www.clipconverter.cc/
http://keepvid.com/
http://www.listentoyoutube.com/

And this software is also great:

http://www.4kdownload.com/