PlaylistPro

PlaylistPro is a free tool for organizing Spotify playlists and Liked Songs. It splits a big playlist or your whole Liked Songs into multiple new playlists by count, genre, BPM, key, or other audio features, moves or copies tracks between playlists with multi-select, sorts by BPM/key/energy and more, and removes duplicates. It also shows your Top Tracks, Top Artists, and Recently Played across different time ranges, with the option to save any of those straight into a playlist.

It has no backend and no database: playlists and tracks are read and written directly between your browser and Spotify. Sign in with Spotify only, no separate account required.