The part that says either ?si= or &si= is only for tracking. You can remove this part of the link and it will still function just the same. It makes the link shorter and also helps protect your privacy. The only important part of a YouTube URL is the video ID. There are two types of URLs:

youtube.com/watch?v=

For this one you can remove everything after and including the ampersand if present.

youtu.be/(videoid)?tracking

For this one you can remove everything after and including the question mark.

Note the exception is if you want to intentionally leave in playlist information you might want to keep that part.

    • XeroxCool@lemmy.worldEnglish
      2·
      4 hours ago

      Just by clicking your link and then going to share it from the YouTube app share button, I get this:

      https://youtu.be/dQw4w9WgXcQ

      That SI code contains something about how the link has been shared, likely telling YouTube that my specific account has been used to share it to whoever clicks it. It probably has info about how I found it as well, such as direct link, yt suggestions, yt homepage, yt Playlist, etc. Now we’re related. Now my analytics will be buddied to yours. Now it that it knows we both like 80s pop music, it’ll tell you to watch some other things I find fascinating. (at least, if the link is opened by someone logged into their yt account)