Open the Spotify app on your phone or computer
Sign in to your account
Find the song, album, or playlist you want
Turn on Download by tapping the download icon (down arrow)
For playlists, open the playlist and tap Download
For albums, open the album and tap Download
To download specific songs, enable the option to save individual tracks if available, then tap the download icon next to each track
On iPhone or Android, switch to Offline mode by tapping Home, then Settings, then Playback, then Offline (if prompted)
On desktop, open the playlist/album and click Download to save tracks for offline listening
Check your downloaded music by going to Your Library, then Downloads
Keep Spotify downloads updated by re-downloading when prompted