The fastest way to cut cellular data use on an iPhone is to turn on Low Data Mode in Settings > Cellular > Cellular Data Options > Data Mode. Then go to Settings > Cellular, see which apps use the most data, and turn off cellular data for the ones that don’t need it. Those apps will only use Wi-Fi.
These settings come from Apple’s View or change cellular data settings on iPhone guide (iOS 27), its Use Low Data Mode article, and its About Connectivity Assist article, which replaced the old Wi-Fi Assist setting in 2026.
1. Turn On Low Data Mode
- Open Settings and tap Cellular.
- Tap Cellular Data Options. On a 5G plan, tap Data Mode.
- Choose or turn on Low Data Mode.
Result: Apple says Low Data Mode pauses automatic updates and background tasks when you’re not on Wi-Fi. With Dual SIM, tap one of your numbers in Settings > Cellular and turn it on there.
What Low Data Mode changes
According to Apple, apps reduce data in different ways, but in general Low Data Mode turns off Background App Refresh, reduces streaming quality, turns off automatic downloads and backups, and pauses iCloud Photos updates. Built-in apps adapt too: the App Store turns off video autoplay and automatic updates, Music turns off automatic downloads and high quality streaming, Podcasts only downloads episodes on Wi-Fi, and News stops prefetching articles. You can also change Background App Refresh on iPhone yourself, for all apps or one at a time.
2. See Which Apps Use the Most Data
- Go to Settings > Cellular.
- Scroll down to the list of apps and tap Show All.
The amount of cellular data each app used appears below its name. System Services, above the app list, shows data used by iOS itself. Apple notes you can’t turn cellular data on or off for individual system services.
3. Turn Off Cellular Data for Specific Apps
In the same list, turn off the switch next to any app. Apple says that when cellular data is off for an app, iPhone uses only Wi-Fi for that service. Streaming, video, and cloud photo apps are usually the biggest users. Autoplaying video in social apps uses data as well, so you can also turn off video autoplay in the X (Twitter) iPhone app. Some backup apps also have their own switch, such as the one that lets you stop Dropbox from using cellular data for uploads. Check that switch if you turn on video uploads in the iPhone Dropbox app, because videos are large. For example, here’s how to turn off cellular data for YouTube on iPhone. Games count too, so you can also check how much data Pokémon GO uses.
For calls specifically, our FaceTime Wi-Fi and cellular guide explains how to allow or restrict mobile data. Turning off cellular access doesn’t turn off FaceTime over Wi-Fi.
4. Check Connectivity Assist (Formerly Wi-Fi Assist)
Apple’s newer Connectivity Assist uses cellular data to improve your connection when Wi-Fi is slow or unusable. It replaces Wi-Fi Assist, which used to be at the bottom of Cellular settings, and it’s on by default if Wi-Fi Assist was on when you updated.
- Go to Settings > Wi-Fi and make sure Wi-Fi is on.
- Scroll down and turn Connectivity Assist off if you want to avoid the extra cellular data.
You can also turn it off for one specific network. Apple says Connectivity Assist isn’t used while you’re roaming internationally or when cellular Low Data Mode is on.
5. Use 5G Auto or LTE
On iPhone 12 and later with a 5G plan, Apple describes these options in Settings > Cellular > Cellular Data Options:
- 5G Auto (under Voice & Data) switches to LTE when 5G doesn’t provide noticeably better performance.
- LTE (under Voice & Data) turns off 5G. See how to turn 5G on or off on an iPhone.
- Avoid Allow More Data on 5G (under Data Mode), which allows higher-quality video and FaceTime HD on 5G.
6. Turn Off Data Roaming When You Travel
In Cellular Data Options, turn off Data Roaming to avoid roaming charges outside your carrier’s network. Apple suggests contacting your carrier about an international plan or adding a travel eSIM to stay connected. If calls misdial while you travel, see how to turn off Dial Assist on iPhone.
7. Use Low Data Mode on Limited Wi-Fi Too
If you connect to a hotspot or another network with a data cap, go to Settings > Wi-Fi, tap the Info button next to the network, and turn on Low Data Mode. Apple says iCloud keeps these Wi-Fi preferences up to date across your devices.
8. Reset the Counter Each Billing Cycle
At the bottom of Settings > Cellular, tap Reset Statistics on the day your plan renews so the numbers match your bill. Apple notes that your carrier has the most accurate usage for the current period.
9. Turn Off Cellular Data Completely
Go to Settings > Cellular and turn off Cellular Data. Apple says all data services, including email, web browsing, and notifications, then use Wi-Fi only. Calls and regular texts still work.
Frequently Asked Questions
Why is my iPhone using cellular data when I’m on Wi-Fi?
Connectivity Assist may be switching to cellular when your Wi-Fi is weak. Turn it off in Settings > Wi-Fi.
Where did Wi-Fi Assist go?
Apple replaced Wi-Fi Assist with Connectivity Assist, which is now in Wi-Fi settings instead of Cellular settings.
Does Low Data Mode slow down my internet?
Apple describes it as restricting background network use. It pauses background activity and can lower streaming quality, so some things may update less often.
Wondering whether texting is part of the problem? See how much data text messaging is using on your iPhone.
If you listen to music on cellular, you can also choose a lower setting in Pandora. Our guide covers how to change audio quality in Pandora on an iPhone.
Social apps can be heavy data users, too. Here is how to stop X (Twitter) from using cellular data on your iPhone. You can also use Facebook only on Wi-Fi on an iPhone. Pictures in newsletters and store emails use data as well, so you may want to stop loading email pictures in the iPhone Mail app.
Like podcasts? See how to subscribe to a podcast on the iPhone. For bedtime listening, you can also set a sleep timer in Apple Podcasts so episodes do not keep playing overnight.
Matthew Burleigh is the founder, head writer, and editor of Solve Your Tech, which he launched in 2012. He has written technology tutorials since 2008 and worked in IT since 2003, including small-business support, IT management, and consulting. He holds Bachelor’s and Master’s degrees in Computer Science from Arizona State University.
Matthew writes practical guides for Windows, iPhone and iPad, Microsoft Office, Outlook, Google apps, and Android. Solve Your Tech’s guides are tested on current devices or checked against official product documentation, with clear steps, sources, and update dates.
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