If your phone loses charge faster than it should, or your mobile data allowance vanishes before the month ends, a background app is often the cause. The good news is that both Android and iPhone show which apps are responsible, and you can limit them without deleting anything.
This guide covers how to identify the culprit, how to restrict its background activity, and what to try when the problem keeps coming back. Menu names vary slightly by phone brand and software version, so I've noted the common differences.
Quick answer
- Open your battery usage screen and look for an app using far more power than its screen time justifies.
- Open your mobile data usage screen and find the app consuming data when you aren't using it.
- Restrict that app's background activity or background data.
- Update the app, and reinstall it if the drain continues.
Why apps use battery and data in the background
Many apps keep working after you close them. Messaging apps check for new messages, photo apps upload to the cloud, weather and social apps refresh content, and navigation or fitness apps may keep using location.
Most of this is normal. The problem starts when an app does it constantly, usually because of a bug, an aggressive sync setting, or a stuck process. Weak signal can make things worse, because the phone's radio uses more power when it struggles to hold a connection.
How to check battery usage
On Android
Go to Settings > Battery > Battery usage. On Pixel phones and similar, you can see usage per app since the last full charge or over the past 24 hours. On Samsung phones, the path is usually Settings > Battery, then the usage chart.
Don't judge by the list alone. An app you used for two hours of video will naturally rank high. What matters is an app near the top that you barely opened. Tap it to see whether the usage was in the foreground or background.
If you see "Android System," "Google Play services," or "Mobile network" near the top, that is usually a symptom, not the cause. Another app may be waking the system or sync services, or your signal may be poor.
On iPhone
Open Settings > Battery and scroll to the usage list. You can switch between the last 24 hours and the last 10 days. Tap Show Activity to see screen-on and screen-off time for each app.
An app with high percentage but little screen time is the one to investigate. Some iOS versions also display a "Background Activity" label under an app's name, which is a useful clue.
How to check which apps use data in the background
On Android
On many phones, go to Settings > Network & internet > SIMs (or Internet) and look for App data usage. On Samsung, look under Settings > Connections > Data usage > Mobile data usage. Open an app's entry to see whether the data was used in the foreground or background.
On iPhone
Go to Settings > Cellular (or Mobile Data) and scroll down to the app list. The numbers show cellular data used since the statistics were last reset. Scroll to the bottom and tap Reset Statistics if you want a clean measurement, though that erases the existing totals.
Keep in mind that these screens only track mobile data. Heavy Wi-Fi use won't appear and won't count against your plan.
How to stop an app from running in the background
Android
Go to Settings > Apps, select the app, and open App battery usage (on some versions, Battery). You'll typically see these choices:
- Optimized: the default; Android manages the app's activity based on how you use it.
- Restricted: sharply limits background work. This is the right choice for an app that misbehaves.
- Unrestricted: allows unlimited background use, so use it sparingly.
Samsung phones have a separate system under Settings > Battery > Background usage limits, where apps can be placed in "Sleeping apps" or "Deep sleeping apps." Deep sleeping apps are stopped from running in the background until you open them.
To cut background data, open the app's page in Settings > Apps, choose Mobile data & Wi-Fi, and turn off Background data. You can also turn on Data Saver under network settings for a broader limit.
iPhone
For battery, go to Settings > General > Background App Refresh. You can turn it off for individual apps, or limit it to Wi-Fi only. To reduce cellular use, go to Settings > Cellular and switch off the app in the list, which blocks it from using mobile data entirely. Low Data Mode in Cellular Data Options is a gentler overall limit.
Swiping an app away in the app switcher usually doesn't help battery on iPhone, and Apple has said that force-quitting apps generally isn't necessary. Use it only for an app that is frozen or clearly misbehaving.
Be careful with messaging and alert apps
Restricting background activity can delay notifications. If you restrict WhatsApp, an email app, or a banking alert app, messages may arrive late or only when you open the app. Start with apps that don't need to reach you instantly, such as shopping, games, and rarely used social apps.
Check location and sync settings too
Location is a frequent hidden cost. On iPhone, go to Settings > Privacy & Security > Location Services. On Android, check Settings > Location > App location permissions. Change apps that don't need constant tracking to "While using the app" or "Ask next time."
Also look at cloud photo backup, auto-playing video, and automatic app updates. If a photo app is uploading a large library over mobile data, switching uploads to Wi-Fi only can save a lot more than blocking the app entirely.
If the drain continues
- Update the app and your system. Battery bugs are often fixed in later versions. Check the app store and your phone's software update screen.
- Restart the phone. This clears stuck processes that can keep an app active.
- Clear the app's cache on Android through Settings > Apps > [app] > Storage. This is generally safe and doesn't delete your login or data, unlike "Clear storage," which does.
- Reinstall the app. Make sure your data is backed up or synced to your account first, because some apps store local data that will be lost.
- Watch for unfamiliar apps. If you find an app you don't remember installing using lots of data or power, uninstall it and run a scan with Google Play Protect on Android. On iPhone, review your installed apps and remove anything you don't recognize.
- Try an alternative. If an app remains a problem after all this, check whether it has a lighter version or a web version. Some apps simply aren't well optimized.
If every app seems to drain the battery, the cause may not be software. An older battery that has lost capacity can look like a background drain. Both Apple and many Android makers offer a battery health check, on iPhone under Settings > Battery > Battery Health & Charging. If health is low, a battery replacement may do more than any setting.
What to do next
Start by finding the one or two apps that use the most power or data relative to how much you actually use them. Restrict those first, then monitor the results for a day or two before changing anything else. Making many changes at once makes it hard to tell what helped, and it can needlessly delay notifications from apps you rely on.
If a restricted app still drains the battery, or the whole phone is unusually hot or slow, contact the app developer or your device manufacturer's support, particularly if the phone is under warranty.