How do I reduce data usage on my iPhone?
If you’re just sending text-based messages, then there’s really no problem. However, when you start sending or receiving photo or audio messages using cellular, you’re going to use a lot more data. If you do anything with video messages, you’ll be burning up data like crazy.
Messages are considered texts and don’t count toward your data usage. Your data usage is also free when you turn on chat features. Learn how to turn on chat features (RCS). Tip: You can send texts over Wi-Fi even if you don’t have cell service.
What uses so much data on my phone?
If your calendar, contacts, and email sync every 15 minutes, it can really drain your data. Have a look under “Settings” > “Accounts” and set your email, calendar, and contact apps to sync data every few hours or set them to only sync when connected to Wi-Fi.
Your apps might also be updating over cellular data, which can burn through your allotment pretty quickly. Turn off automatic app updates under the iTunes and App Store settings. Your next move should be to make sure your photos only backup to iCloud when you’re on Wi-Fi.
7 ways to seriously cut back on iPhone data usage