The best alternatives to Playlist Sorter are Playlist Machinery, Muru Music, and SpotifyEditor. If these 3 options don't work for you, we've listed a few more alternatives below.
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AssemblyAI— Speech-to-Text API with superhuman accuracy
Backtube is a playlist app where you can request recommendations through themes and create your own playlists and link them to other themes. You can listen to the playlists on the app and search and listen to Youtube and Bandcamp music catalog as well.