See Unlisted Videos Youtube Extension

YouTube’s privacy model is clear:

In other words, if an unlisted video exists, only Google/YouTube knows about it – and they won’t share that list with anyone, including browser extensions. see unlisted videos youtube extension

These extensions scan the HTML of the webpage you are currently viewing. If a creator has embedded an unlisted YouTube video in a blog post, forum thread, or social media comment, these tools will detect it. YouTube’s privacy model is clear:

No legitimate extension can brute-force find unlisted YouTube videos. YouTube’s backend is secure. Unlisted videos are not stored in a public-facing index. An extension cannot "hack" YouTube to reveal links that the owner has not shared publicly. In other words, if an unlisted video exists,

However, extensions can help you in three specific scenarios: