Answer:
Spotify stores songs on your devices' cache. This enables the music to start immediately after pressing Play. The amount of music stored in the cache shouldn't keep growing as new songs replace stored songs that haven't been listened to for a while. The more songs you have saved for Offline use, the more space your cache will take up however.
Q: The Spotify app is taking up many GB's of storage, how can free-up space?
A: On mobile devices you can clear your cache when you find that your cache is growing quite large. Here's how:
Android:
iOS:
Q: Can I change the location where my music is being stored?
A: It's possible to change the location where your music is stored. If your Android device supports an SD card, you can choose to have the music stored there. On a Desktop computer you can change the location as well. Here's how to change the storage location on Android and Desktop:
Android:
Desktop:
Note: On iOS devices you can't change the storage location.
Q: I'm still experiencing an issue, what can I do?
A: For all other things we recommend resetting your cache by performing a clean reinstall on the affected device. Keep in mind that you'll need to re-download all your offline songs once you've done this.