With the Wi-Fi Assist feature, your iPhone automatically switches to mobile data when Wi-Fi connectivity is poor. When this feature is on, your phone might use more mobile data than normal, and it will count towards the data usage in your plan.
- Touch Settings.
- Touch Cellular.
- Scroll to and touch the Wi-Fi Assist slider to change the setting (e.g., from off to on).
- Wi-Fi Assist is now on.Touch the Wi-Fi Assist slider again to turn it off.