Will my iPhone automatically use WiFi instead of data?
As John said, the iPhone will switch to known WiFi networks automatically, HOWEVER, it will not use WiFi when on standby as WiFi is a continuous power drain.
So if the phone is asleep and an app requires data it will use cellular data..
Why is my phone using data when connected to WiFi?
Go to Settings/Cellular, scroll to the bottom, and turn off WiFi Assist. Note that the phone will only use WiFi over cellular data when the screen is on or the phone is connected to power. … Based on the amount of data used, it’s also possible that you have an app that is misbehaving and using excessive data.
Should you turn mobile data off when using WiFi?
On iOS, it’s Wi-Fi Assist. On Android, it’s Adaptive Wi-Fi. Either way, it’s something you should consider turning off if you use too much data each month. … Turn it off and your phone will no longer automatically switch to cellular data when the WiFi signal gets spotty.
What happens if you leave your mobile data on?
When you keep your mobile data on then it effects your battery and the background apps which go on syncing. When your mobile data is on, your location is at high accuracy, which again drains your battery life. Settings/Data usage/Apps.
How do you tell if your phone is using WiFi or data?
In settings, disable mobile data and if you still get Internet then you know. This also guarantees wifi only. Also if connected to wifi, when you drag down the notification bar, it will show wifi connected. Or, as op said, go to settings, click wifi and it will show you.