If Samsung Galaxy S6 is connected to wifi does it still pull data from 4G tower

[AC Question]

If Samsung Galaxy S6 is connected to wifi is it still using 4G data

 

[the tall guy]

Hi - no, if you are connected to the WiFi you will be using the WiFi not the phones data. The S6 comes with a setting option called "Download Booster" which can be found in the settings menu under "more connection settings" make sure this is turned off. When downloading a larger file / app if the download booster is enabled it will use both your data and WiFi to download the file / app faster.

 

[AlphaTango414]

It's still possible for it to use some data but not much. If you are worried or have very limited data, you can always turn your mobile data off while using wifi.
*Note that not all varients of the S6 has Download Booster.