A new update allows you to save unlimited songs to your Spotify libraries, but the 10,000 song limit will still apply to playlists and downloaded tracks.
The 10,000 song limit on Spotify libraries has been lifted, allowing you to save as many tracks as you like. This has been a common request from Spotify Free and Premium users for a while. The update has started rolling out now, so you should never see the “All filled up” notification again.
Unfortunately the 10,000 track limit still applies to playlists and offline tracks. This is likely to stop users downloading all of Spotify, blocking the apps network access, then cancelling their subscription. Netflix has similar offline restrictions in place, such as expiring content and limiting the number of times a video can be downloaded.