Does using facetime use data over Wi-Fi?

I have an iPhone 5 and my facetime is restricted to Wi-Fi use only and addition to that my cellular data is off and I'm connected to Wi-Fi. But after my facetime call there's always MB after it?
Example 21 MB. Even though I'm on Wi-Fi and cellular data is off. Can anyone tell me if I'm being charged for this? Is it using cellular data?

If you are connected over Wi-Fi, then you're not using anything off your cellular data, so you will not be charged as part of your cellular data plan.

  • Why does Netflix keep pausing and playing over and over? I'm using it on my iphone 4. And I have checked my connections over and over I've uninstalled reinstalled, signed in signed back and everything else that the troubleshoot website has recommend. And it's gotten annoying. It didn't start doing this as much until I updated the app before the ios 7 release. I'm currently using the trial for netflix and my laptop doesn't work so I can get it on anything but my phone.
  • Why does my iphone use data over night when cellular data is turned off? Every night I turn off cellular data and leave the iPhone on and one day I wake up and check my data manager and see i have already used 25 MB please help!
  • Over using data on unlimited straight talk plan? I have a straight talk iphone and they turned off all my data completely saying i "overused" my unlimited data plan. So i have to wait until my original service runs out which was just three days thank god, to add another 30 day unlimited plan. My only question is. Will my phone still work just fine like it did before this mishap. Can anyone tell me if this happened to them as well? And did your phone work with a new minute card? Or did you have to bjuy a whole new phone also?
  • My iPhone 4S keeps turning off over and over and over again? I was on my phone just listening to OM&M on pandora and going on twitter when all of a sudden it shut off and now it's stuck on the turning off screen for like an hour or two. What do i do I'm FREAKING OUT.