YouTube

googlevideo.com

ytimg.com

youtube.com

youtube-ui.l.google.com

ytimg.l.google.com

ytstatic.l.google.com

youtubei.googleapis.com

The website itself (works for PCs):

youtube.com

Thumbnail domains (PCs, tablets, and phones):

ytimg.com

ytimg.l.google.com

Youtube Applications:

youtube.l.google.com

googlevideo.com

youtube.com

www.youtube-nocookie.com

c.youtube.com

ytimg.l.google.com

googlesyndication.com

ytimg.com

accounts.google.com

m.youtube.com (specific to mobile)

googlevideo.com (mostly for mobile, required for youtube app for mobile)

youtube.l.google.com

youtube-ui.l.google.com, googlevideo.com, ytimg.com, android.googleapis.com, googleapis.com, youtube.com, youtu.be, yt3.ggpht.com

googlevideo.com

ytimg.com

youtube.com

youtube-ui.l.google.com

ytimg.l.google.com

ytstatic.l.google.com

youtubei.googleapis.com

youtube.com

www.youtube-nocookie.com

c.youtube.com

ytimg.l.google.com

googlesyndication.com

ytimg.com

accounts.google.com

youtube.l.google.com

youtube-ui.l.google.com, googlevideo.com, ytimg.com, android.googleapis.com, googleapis.com, youtube.com, youtu.be, yt3.ggpht.com