Save Data
Hidden within your Cellular Data Options is a new toggle for Low Data Mode which can help you conserve data if you’re running near the edge of your monthly allotment.
This is a global setting that will tell third-party apps that respect it, such as Apple’s own Music and Photos apps, as well as Spotify’s latest update, to essentially start sipping data to help you avoid overage charges.
It also turns off Background App Refresh, automatic downloads of things like app updates and backups, and reduces bitrates on FaceTime calls and lowers the streaming quality in Apple Music.