Android data usage shows significant usage even without SIM card I just purchased a Nexus 4 to replace an old Android phone.  After learning my lesson last time, I've decided to start the phone without a SIM card and sync all my apps etcetera over Wi-Fi so it doesn't chew through massive amounts of cellular data.  At this point, the phone is brand new, has never had a SIM card inserted, and I go into Settings > Data Usage.  My phone is reporting ~751MB of data usage.  I assumed there would be 0 MB data usage, given that I haven't even inserted a SIM.  I don't believe the data usage count is syncing from my old phone, as I typically only use a few MB a month, which viewing the data usage on my old handset confirms.

Is there an explanation for why a Nexus 4 that has never had a SIM card in it would report substantial data usage, or is this a bug?
The Data Usage screen can show both Mobile Data and Wi-Fi usage (but only shows one by default).



You're almost certainly seeing your Wi-fi usage, 750MB doesn't sound unlikely for a new device that will have downloaded settings, apps, contacts, and probably OS updates.

If you have a SIM card in your phone then the Data Usage app defaults to only showing Mobile Data usage, but there is a menu option to allow you to set it to show Wi-Fi data usage too.



I assume that if the device has never had a SIM card inserted, then it will default to showing Wi-Fi usage, as that's the only data usage it's used.

(screenshots from a Galaxy Nexus, so it should work the same way)