does my cellphone use data when connected via wifi
Yes it does use your data. Even though it says you're connected to wifi the hot spot overrides it & uses your cellular data. I finally figured this out after months of questioning my cellular company as to how it was possible I could use that much data.ou cannot use your Wi-Fi connection for Internet connectivity while other devices are using Wi-Fi for Personal Hotspot. You can share only a cellular data connection; you cannot share a Wi-Fi connection. As seen here: http://support.apple.com/kb/ht4517. share | improve this answer.