si?The share identifier YouTube and Spotify attach when you tap Share: a token that ties every open of that link back to the specific share that created it.
Tap Share in YouTube and the youtu.be link arrives with si= and sixteen characters of token. Spotify does the same on open.spotify.com track, album and playlist links, with a longer token. YouTube added its version in mid 2023; Spotify has carried one for years.
The token identifies the share event itself. When someone opens your link, the platform learns that this particular share, from your account, at that moment, produced the visit, and can connect the opener to you. Spotify's own privacy documentation describes share links as a way of measuring how content spreads between users.
The video plays and the song streams exactly the same without it. Note that si is not the timestamp: the t= parameter that jumps to a moment in a YouTube video is functional, and worth keeping when you meant it.
Yes. The content loads identically without it. Remove it and the platform simply cannot tie the open back to your share. Keep the t= timestamp parameter on YouTube links if you set one on purpose; that one actually does something.
Rather's Link Shortener strips si and hundreds of parameters like it, right in the address bar and in everything you copy or share. Free, open source, no account, no data collection, and the page you are on never breaks: the cleanup happens after the site has already loaded.