: Some tools, such as the YouTube Deleted Videos: Track and Restore extension, monitor your playlists and use metadata to help find alternative versions or cached links of videos that have changed visibility. Popular Extensions and Tools
This paper examines the mechanisms, tools, and ethical considerations surrounding the discovery of unlisted YouTube videos through browser extensions and external databases. The Mechanics of Unlisted Content see unlisted videos youtube extension
If an extension fails, you can often find unlisted links using Google’s advanced search operators: : Some tools, such as the YouTube Deleted