Data usage is the amount of data your phone uploads or downloads in a given period over your carrier's cellular network or a Wi-Fi network. You can review your data usage and change settings to conserve data.
Quick setting: From the lock screen or home screen, swipe the status bar down with two fingers and touch
(dual SIM) or
(single SIM). Then turn Cellular data off
or on
. To see other options, touch More settings.
When you turn off data usage over your cellular network, you can still use data by connecting to a Wi-Fi network.
Cellular data must be ON if you want to:
Go to Settings > Data usage.
Turn Cellular data off
or on
.
Sometimes it's easy to exceed your data plan limit without realizing it. To avoid surprises, set a usage warning that notifies you when you’re close to your limit, and set a usage limit that turns off cellular data when the limit is reached.
Go to Settings > Data usage.
To set the warning level, drag the right side of the warning bar up/down.

When your data usage reaches the specified level, you'll receive a notification.
To set the usage limit, drag the right side of the limit bar up/down.
When your data usage reaches the specified level, your phone will turn off data usage.
Even when you’re not using them, most apps sync data in the background.
To minimize data usage, you can restrict background data usage for individual apps, or you can restrict all background data usage.
When you restrict background data, you will not receive notifications from apps that typically sync in the background (like Gmail) until you open the app; then data syncs as usual.
To restrict background data usage for individual apps:
To restrict background data usage for all apps:
Go to Settings > Data usage.
If your phone has two SIMs, cellular data is active on only one SIM at a time. You can control which SIM is used.