Phone help

How to Reduce Mobile Data Usage on Your Phone

By TheTruthSpy Editor · Founder and editorPublished October 27, 202611 min read

A phone showing a mobile data usage ring nearly full, on a train table by the window beside earbuds, a bank card and a ticket

It’s the 12th of the month and your network has just texted: you’ve used 80% of your data. Most people’s first move is to switch mobile data off and hope. A better one is to spend two minutes on the per-app list, because one or two apps often account for most of the usage, and one setting in each usually fixes it.

This article works in that order. First find the real culprits, then change the settings that matter, with menu paths for iPhone and Android. There is also a worked example of a month’s data showing how much a single setting can save, and a 10-minute audit you can repeat whenever the bill looks wrong.

The short version

Check which apps use the most data before changing anything. Reset the figures at the start of each billing month so they mean something.
Video is almost always the biggest user. Changing a streaming app’s quality setting on mobile data can save more than every other change put together.
Turn on Low Data Mode (iPhone) or Data Saver (Android) to stop background updates, backups and auto-downloads using mobile data.
Check the settings that quietly switch you to mobile data when Wi-Fi is weak, and set photo backups and app updates to Wi-Fi only.
Download maps, music and shows on Wi-Fi before you travel.

Find out which apps are using your data

Your phone keeps a running total for each app. The catch is the time period: on an iPhone, the total counts from the last time you reset it, which may be months ago.

iPhone: open Settings → Mobile Service (Mobile Data on older versions of iOS) and scroll down. Each app is listed with the data it has used. System Services covers the phone’s own features. Scroll to the bottom and tap Reset Statistics on the day your billing month starts, so the next reading covers one month.
Pixel and most Android phones: open Settings → Network & internet → SIMs → App data usage. You can pick the date range and set the day your billing cycle starts, so the totals reset themselves.
Samsung: open Settings → Connections → Data usage → Mobile data usage. The billing cycle start date is set on the same screen.

Your phone and your network can disagree slightly. Google points out that carriers may measure usage differently, so for billing purposes, your network’s app is the one that counts.

A phone screen listing apps by mobile data used, with a video app far ahead of messaging, maps and music — On most phones the list is lopsided: one video or social app often uses more than everything else combined.

Set a warning before you run out

Android can warn you, or stop mobile data altogether, at a figure you choose. On a Pixel, go to Settings → Network & internet → SIMs → Data warning & limit, turn on Set data warning and enter an amount a little below your allowance. Set data limit switches mobile data off when you reach it. Samsung has the same options in Settings → Connections → Data usage.

iPhones don’t have a built-in data limit. Instead, use your network’s app, which can usually send usage alerts, and check the per-app list once a week until you know your pattern. Set any warning slightly early, because the phone and the network can count slightly differently.

What common activities actually use

These figures come from the services’ own help pages and are approximate. Real use varies with the app, the screen and the connection, and other services set their own quality levels.

Activity	Approximate data	Where the figure comes from
Video, mobile “save data” setting	About 1 GB per 6 hours	Netflix help centre
Video, mobile “automatic” setting	About 1 GB per 4 hours	Netflix help centre
Video, mobile “maximum data” setting	1 GB per 20 minutes or more (3 GB an hour)	Netflix help centre
Video, 4K on a TV or computer	Up to 7 GB an hour	Netflix help centre
Music, normal quality (about 96 kbit/s)	About 43 MB an hour	Worked out from Spotify’s stated bitrate
Music, very high quality (about 320 kbit/s)	About 144 MB an hour	Worked out from Spotify’s stated bitrate
Uploading 4K phone video	Roughly 170 MB per minute filmed	The estimate an iPhone shows in Settings → Camera → Record Video for 4K at 30 frames per second

The gap is the point: an hour of video at the highest mobile setting can use as much data as 70 hours of normal-quality music. Spotify’s Lossless option, for Premium subscribers, streams far larger files than Very high, so keep it for Wi-Fi. Messaging, email and browsing are usually small by comparison, unless they are full of video.

A worked example: one month, one setting

Say you have a 10 GB plan, commute by train 20 days a month, and keep running out. Here is a hypothetical month using the figures above. The last row is a placeholder for everything else; swap in the figure from your own per-app list.

Activity in the month	Estimated before	Setting changed	Estimated after
Streaming shows, 30 minutes a day (10 hours)	About 30 GB at the highest mobile setting	Video app set to its data-saving option on mobile	About 1.7 GB
Music, an hour a day (20 hours)	About 2.9 GB at very high	Mobile streaming quality set to normal	About 0.9 GB
Backing up 10 minutes of 4K video	About 1.7 GB	Photo backup set to Wi-Fi only	0 GB (it uploads at home)
Messages, maps, email, browsing	2 GB (placeholder)	None	2 GB
Total	About 37 GB		About 4.6 GB

Changing only the video setting takes this month from about 37 GB to about 8 GB, back inside the plan. The other two changes save around 3.7 GB between them. That is why it pays to look at the list first: if you had turned off background refresh for twenty small apps instead, the total would barely have moved.

Downloading the shows at home on Wi-Fi would take the video row to zero. Many apps start on an automatic setting that uses far less than the highest one, so check what yours is actually set to before assuming video is the problem.

Bar chart comparing a month's data before and after changing settings, against a 10 GB plan line — In the example, video is almost the whole of the “before” bar, so one setting brings the month back under the plan.

Video and music apps: the setting that saves most

Most streaming apps have a separate quality setting for mobile data, usually buried a couple of levels down. Brand names are below because the menus differ; other apps have similar options.

YouTube: tap your profile picture, then Settings → Video quality preferences, and under mobile networks choose Data saver.
Netflix: tap My Netflix, open App Settings → Mobile Data Usage and choose Save Data, or Wi-Fi Only if you download before you go out.
Spotify: tap your profile picture, then Settings and privacy, and under Media quality set mobile streaming lower than Wi-Fi.

Social feeds are the other half of the problem. Videos that start playing as you scroll use data whether you watch them or not. Instagram has a Use less mobile data option in its media quality settings, Facebook lets you set video autoplay to never under its media settings, and TikTok has a Data Saver switch in Settings and privacy. These menus move often, so search the app’s settings if the path has changed. In WhatsApp, Settings → Storage and data → Media auto-download controls which photos and videos download on mobile data.

A phone streaming a video on a train table by the window, with the quality badge switched from HD to SD — On a phone-sized screen the drop from HD is modest; on the bill, at up to 3 GB an hour, it’s the biggest line.

Low Data Mode and Data Saver

These switches tell the phone and its apps to hold back on anything that isn’t happening in front of you.

iPhone: go to Settings → Mobile Service → Mobile Data Options and turn on Low Data Mode. On 5G iPhones, it’s under Data Mode. With two lines, tap the number first. Apple says it turns off Background App Refresh, lowers streaming quality, stops automatic downloads and backups, and pauses iCloud Photos updates.
Android: go to Settings → Network & internet → Data Saver (Samsung: Settings → Connections → Data usage → Data saver). Google says most apps then get background data only on Wi-Fi. Use Unrestricted data to exempt apps that must stay live, such as your messaging app.

The trade-off is that some apps won’t refresh until you open them. On a 5G iPhone, it’s also worth checking that Data Mode isn’t set to Allow More Data on 5G, which Apple says enables higher data-usage features. Apple describes Standard, the middle option, as generally the default.

Two phones compared: background uploads and downloads running with data saver off, and paused with it switched on — One switch pauses the background updates and downloads that you wouldn’t otherwise notice.

When weak Wi-Fi quietly switches you to mobile data

Phones are designed to keep you connected, so when Wi-Fi is poor they may use mobile data without telling you. That’s useful on a bad café connection, but it can use a lot of data at home if your Wi-Fi drops in one room.

iPhone: Wi-Fi Assist is at the bottom of Settings → Mobile Service. Apple says it works only with apps on screen, doesn’t switch while you’re roaming, and isn’t used by some streaming apps.
Pixel: look in Settings → Network & internet → Adaptive connectivity, where recent versions have a separate switch for moving to mobile data when Wi-Fi is poor.
Samsung: Settings → Connections → Wi-Fi, then the three-dot menu, Intelligent Wi-Fi and Switch to mobile data. Names vary between One UI versions.

Background data, app updates and photo backups

For a single app you don’t want using mobile data at all, turn off its switch in the per-app list on an iPhone. On a Pixel, go to Settings → Apps, choose the app, tap Mobile data & Wi-Fi and turn off Background data; on a Samsung, it’s Allow background data usage under the app’s Mobile data. On an iPhone, Settings → General → Background App Refresh can be set to Wi-Fi only.

App updates can be large. On an iPhone, go to Settings → Apps → App Store and, under mobile data, turn off automatic downloads. In Google Play, tap your profile picture, then Settings → Network preferences → Auto-update apps, and choose to update over Wi-Fi only.

Photo backup is easy to miss, because it happens when you’re out taking pictures. On an iPhone, turn off Mobile Data in Settings → Apps → Photos. In Google Photos, tap your profile picture, then Photos settings → Backup → Mobile data usage, where you can set a daily limit and turn off Back up videos over data.

A phone on a hall table beside a home router, backing up photos over Wi-Fi to the cloud — With backup set to Wi-Fi only, a day’s photos wait on the phone and upload once you’re home on your own Wi-Fi.

Maps, travel and hotspots

Downloaded maps work with no signal at all, which also helps abroad. In Google Maps, tap your profile picture, then Offline maps → Select your own map. Google says offline maps expire, updating themselves on Wi-Fi when they are close to it, and that walking, cycling and public transport directions aren’t available offline. Apple Maps (iOS 17 or later) has Offline Maps under your profile picture and keeps turn-by-turn navigation working offline. Downloads take space, so check how much storage you have free first.

Hotspots cause surprise bills because a laptop treats your phone like any other Wi-Fi and starts syncing files and downloading updates. On Windows, go to Settings → Network & internet → Wi-Fi, select the hotspot and turn on Metered connection. On a Mac, turn on Low Data Mode in the network’s Details under System Settings → Wi-Fi.

A phone resting on a rock with mountains behind, showing a downloaded offline map with a walking route — An area downloaded at home works when the signal disappears, and uses no data on the day.

A phone sharing its connection to a laptop on a café table, with a large update download paused on the laptop — Marking the hotspot as metered stops the laptop treating it like unlimited home broadband.

The 10-minute data audit

Run through this at the start of a billing month, or whenever usage jumps.

Open the per-app list and note the top three apps (1 minute).
Check the time period covers this billing month; reset or set the cycle date (1 minute).
Set the mobile quality in each video or music app in your top three (2 minutes).
Turn off autoplay or turn on data saving in your main social app (1 minute).
Set photo backup to Wi-Fi only (1 minute).
Set app store updates to Wi-Fi only (1 minute).
Decide about Wi-Fi Assist or auto-switching (30 seconds).
Turn on Low Data Mode or Data Saver if you’re often near your limit (30 seconds).
On Android, set a data warning just below your allowance (1 minute).
Put a reminder in your calendar to check the list again in a week (1 minute).

A clipboard with a ten-item tick list, a timer showing ten minutes and a phone face down on a desk — Ten minutes once a month is usually enough, because the same two or three apps tend to be responsible.

What if you’re still running out

System Services is high: on an iPhone, tap System Services to see which part of the phone is responsible, such as software updates or backups.
Usage jumps on days you didn’t use the phone much: look for a hotspot you left on, a tablet or laptop connected to it, or a cloud storage app uploading files.
One app’s usage suddenly rises: check its settings after an update, since some updates reset quality options, and restart the phone.
The numbers still don’t add up: compare with your network’s app. If the network shows much more than the phone, ask your network for an itemised breakdown.

Frequently asked questions

Does watching something I downloaded use mobile data?

No. Once a show, playlist or map is on the phone, playing it uses no data. Set downloads to Wi-Fi only so they don’t start over mobile data.

Does 5G use more data than 4G?

Not for the same thing, but faster connections let apps choose higher quality automatically. That’s why the Data Mode setting on 5G iPhones, and each app’s own quality setting, matter more than the network type.

Is it worth turning mobile data off completely?

Only as a stopgap. You lose messages, maps and alerts, and it doesn’t fix whatever used the data. Low Data Mode or Data Saver keeps the basics working.

My child keeps running out of data. What can I do?

Go through the audit with them, so they can see which app uses it. On an iPhone with Screen Time set up, you can also stop changes to mobile data settings under Content & Privacy Restrictions, agreed with them rather than done behind their back.

Sources and further reading

Written by

TheTruthSpy Editor · Founder and editor

Parent of [two] children aged [9 and 14], and has run [TheTruthSpy] on the family's Android phones since [2022].

I started [TheTruthSpy] after trying to find a parental control app that would tell me what it could and could not see. Most of them would not, so I ended up building one that does. I write the guides on this site myself, on the phones in my own house — [a Samsung Galaxy A-series and a Pixel], both on [Android 14]. When a page says a menu sits three taps deep, I counted the taps. When a page says a feature cannot do something, it is because I tried it and it did not work. I am not a security researcher and I do not pretend to be one. What I have is [three] years of living with these tools in a house with teenagers, and a strong dislike of software that overstates itself.

245 guides · Website · How we write these

Looking for a tool to go with this? TheTruthSpy is a free parental control app for Android that stays visible on the child's phone. If it fits your family, see what the app does.

Keep reading

Related guides

Parental controls your child can see

Location, screen time limits, a web filter and alerts from notifications — free, and visible on your child's phone. Pair a phone in about ten minutes.

Get the app free See every feature

Android · Free to set up · Visible on your child's phone