You can use Wi-Fi as an alternative to the mobile network when establishing an internet connection. This way, your mobile phone doesn't use mobile data.
Step 1 of 4
Find "Wi-Fi"
Tap Settings.
Step 2 of 4
Find "Wi-Fi"
Tap Wi-Fi.
Step 3 of 4
Turn Wi-Fi on or off
Tap the indicator next to "Wi-Fi" to turn the function on or off.
Step 4 of 4
Return to the home screen
Slide your finger upwards starting from the bottom of the screen to return to the home screen.