iPhone Using Too Much Cellular Data? Try These Fixes

Common causes

• Connectivity Assist (formerly Wi-Fi Assist) using cellular data when Wi-Fi is slow or weak
• Data Mode set to Allow More Data on 5G on iPhone 12 or later
• High Quality cellular streaming turned on in Music or the TV app
• An Exchange ActiveSync account that keeps using cellular data after you turn it off for Mail and Calendar
• Automatic updates and background tasks allowed on cellular

Step-by-Step Solutions

Start by checking which apps use cellular data, then work through the settings below in order.

1. 1

   Step 1: See which apps use cellular data

   The Cellular screen lists how much cellular data each app and System Services have used.

   Open Settings and tap Cellular, or Mobile Data. On iPad, you might see Cellular Data instead. Scroll down to find which apps are using cellular data.

   Tap System Services in the list under Cellular Data to see the usage for individual System Services. If your device is enrolled in Mobile Device Management, tap System Services and then Corporate Accounts to view related data.

   The statistics cover a current period. To reset them, open Settings, tap Cellular, then tap Reset Statistics.

   Good to know

   For the most accurate cellular data usage from a current period, contact your carrier. With Dual SIM, the screen shows usage for your selected cellular data number.

2. 2

   Step 2: Turn off Connectivity Assist

   Connectivity Assist (formerly Wi-Fi Assist) uses cellular data when Wi-Fi is slow or unusable.

   Connectivity Assist uses cellular data along with Wi-Fi when Wi-Fi is weak, busy or not connected to the internet. With it turned on, you might use more cellular data. It replaces Wi-Fi Assist, which was in Cellular settings, and if Wi-Fi Assist was on when you updated your software, Connectivity Assist is on by default.

   Update your iPhone to the latest iOS. Then open Settings, tap Wi-Fi, make sure Wi-Fi is turned on, scroll down and turn off Connectivity Assist.

   Good to know

   Connectivity Assist isn’t used when your iPhone is international roaming, in cellular Low Data Mode, or with some third-party apps that stream audio and video.

3. 3

   Step 3: Check Data Mode on 5G

   On iPhone 12 or later, Allow More Data on 5G uses more cellular data.

   Open Settings, tap Cellular, then Cellular Data Options, or tap Mobile Data, then Mobile Data Options. If you use Dual SIM, choose the number you want to change. Tap Data Mode and look at which option is selected.

   Allow More Data on 5G enables higher data-usage features, such as higher-quality FaceTime, high-definition content on Apple TV, Apple Music songs and videos, iOS updates over cellular and automatic iCloud backups. It also allows third-party apps to use more cellular data. It is the default with some unlimited-data plans, depending on your carrier.

   Standard allows automatic updates and background tasks on cellular and uses standard quality settings for video and FaceTime. Low Data Mode pauses automatic updates and background tasks.

   Good to know

   With Allow More Data on 5G, your iPhone can automatically use 5G instead of Wi-Fi when Wi-Fi is slow or insecure on a network you visit occasionally. To turn this off or on for a certain network, open Settings, tap Wi-Fi, tap the info button next to the network, then tap Use Wi-Fi for Internet.

4. 4

   Step 4: Check Music and TV streaming quality

   High Quality cellular streaming in Music and the TV app uses more cellular data.

   For Music, open Settings, tap Apps, then Music, then Audio Quality, and check whether Cellular Streaming is set to High Quality.

   For TV, open Settings, tap TV, then tap Settings or Mobile Data. Check whether Use Cellular Data is on and whether High Quality is selected.

   Good to know

   High Quality content might also take longer to start playing.

5. 5

   Step 5: Check an Exchange ActiveSync account

   An Exchange ActiveSync account might keep using cellular data even after you turn it off for Mail and Calendar.

   If you use an Exchange ActiveSync account, open Settings, tap Cellular, then tap System Services to see how much cellular data the account is using.

6. 6

   Step 6: Turn off cellular data for apps

   You can stop individual apps from using cellular data, so they use only Wi-Fi.

   Open Settings, tap Cellular, scroll down to the list of apps and turn off cellular data for any app you don’t want using it. When cellular data is off for an app, it uses only Wi-Fi for data.

   Cellular data can’t be turned on or off for individual System Services. To stop all apps and services from using the cellular network, tap the slider next to Cellular Data.

7. 7

   Step 7: Turn on Low Data Mode

   Low Data Mode restricts background network use, and you can turn it on separately for cellular and Wi-Fi.

   Open Settings and tap Cellular. On a 5G plan, tap Cellular Data Options, select Data Mode, then turn on Low Data Mode. On an LTE or 4G plan, tap Cellular Data Options, then turn on Low Data Mode. With Dual SIM, tap one of your numbers, then turn on Low Data Mode.

   For Wi-Fi, open Settings, tap Wi-Fi, tap the Info button next to the network you’re connected to, then turn on Low Data Mode. Different apps reduce data use in different ways, but in general Low Data Mode:

   • Stops using network data when you’re not actively using those apps
   • Turns off Background App Refresh
   • Reduces the quality of streaming content
   • Turns off automatic downloads and backups
   • Pauses updates for services such as iCloud Photos

   Good to know

   Your Low Data Mode settings might vary depending on your carrier.

Frequently Asked Questions