Soundiiz supports both the YouTube and YouTube Music platforms.
The main difference is how we deal with the matching process on these platforms and how we retrieve metadata.
When transferring a playlist or tracks to YouTube, we match to the most popular videos in the YouTube catalog.
When transferring a playlist or tracks to YouTube Music, we match them as closely as possible to audio-only videos in the YouTube Music catalog.
About metadata, we are able to retrieve proper "music" metadatas when you have connected YouTube Music instead of YouTube. If your playlists are mainly audio-only, we recommend you always use YouTube Music on Soundiiz.
Also, on Soundiiz, if you are connecting to the YouTube Music platform and retrieving the video's name, we can also retrieve the artist's name. That could be very useful if you want to export to another music service or a file (CSV, TXT...).
And finally, be aware that YouTube and YouTube Music share the same user library. That means a playlist created under your YouTube account is also available on your YouTube Music account as long as you use the same Google account.