What we can read, and what stays behind
Adding a song to your library and liking it are two different gestures in YouTube Music, and only the second one leaves a trace we can read. That is why a library full of music can show up here almost empty.
The setting that hides half of them
YouTube and YouTube Music share one account and two piles of likes, one for videos and one for songs. In YouTube Music, the option called Show your liked music from YouTube decides whether the two are merged. With it off, everything you liked on the YouTube side stays invisible here.
The other half of the problem is the channel. One Google account can carry several, each with its own likes and playlists, and we see only the one you connected. If your list looks like someone else's, that is usually why.
Frequently Asked Questions
My library is full but Soundiiz shows almost nothing.
Then your music was added to the library without being liked. Like what you want to move, reload Soundiiz, and it appears.
I see music videos I never wanted.
You connected YouTube rather than YouTube Music, or the two piles of likes are merged. Connect YouTube Music for audio only.
A playlist is listed but arrives short.
The missing songs are your own uploaded files, which never leave the app. Our page on missing songs in YouTube Music explains how to spot them.
I transferred TO YouTube Music and cannot find it.
That is the other direction, and it has its own page. Liked songs land in a playlist made for you, and artists land in your subscriptions.