Нашёл 18 млн ответов for 'YouTube videos and photos'.
https://www.youtube.com/?%01
https://m.youtube.com/
https://www.facebook.com/youtube
https://www.facebook.com/youtubetabapp/
https://twitter.com/youtube
https://metricool.com/youtube-image-and-videos-dimensions/
https://support.google.com/youtube/answer/72431?hl=en
https://support.google.com/youtube/thread/41355393?hl=en
https://support.google.com/youtube/answer/6178631?hl=en