The answer is no.
Generally, when your phone is connected to your home or any other Wi-Fi network, it will not connect to the 5G, 4G, 3G, or any type of wireless carrier network.
Any data used via Wi-Fi will not count toward your data plan.
Do I need to turn off mobile data when using WiFi?
When the mobile data is ON and you turn on the WiFi, it automatically gets connected to a WiFi network which it recognises and stops using the mobile data. So you don’t have to turn off the mobile data when you turn on WiFi.
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.
Why am I being charged for data when using WiFi?
You can turn your wifi and cellular data on and you will get charged for data even if you are browsing the internet and using apps through wifi. So if you at home and you have a wifi signal then use only wifi and keep the cellular data turned off.
Is it better to leave WiFi on or off?
If you’re about to embark on a day-long trip and won’t be around any Wifi for it, then yes, turning off Wifi will save your more battery, but there’s no real need to shut it off if you’re just going between one Wifi zone and another, such as between home and work or out to run some errands.