Even as the world has more and more options for seemingly unlimited high-speed data, there are plenty of times when you might want to reduce your data usage. Perhaps you’re trying to avoid running over a data cap while traveling, or maybe you’re sharing a Wi-Fi network with a very slow Internet connection. Either way, you can prevent your iPhone from using more data than necessary by enabling Low Data Mode. This works with iOS 13 and later.
For cellular, find the switch in Settings > Cellular > Cellular Data Options. For Wi-Fi, in Settings > Wi-Fi, tap the (i) button next to the network you’re using to enable Low Data Mode for that network. In either case, make sure to turn Low Data Mode off once you no longer need it to avoid getting confused about why background sync tasks (photo syncing, app updates) don’t complete. For more information about what Low Data Mode does, you can read Apple’s article on the subject.
If you are an existing customer who needs help with this or if you have other questions, or if you are in San Francisco and interested in becoming a client I invite you to book an appointment with me. Otherwise, you may wish to contact Apple Support or to find a local Apple consultant.