Sudden excessive data usage

[Steve20]

I have a iphone 6. This evening I was watching tv and suddenly I was receiving multiple text messages saying my data usage was 75% then 90 and then 100% for no reason. I looked online at my data usage and it says I used just over half a gig in a 5 minute span. That's impossible as I was not using my phone at that time and it was connected to my home wifi as well. Very confused...

[Nighthawk · Accepted solution]

Half a gig in 5 minutes? Easy to do. If your phone dropped from wifi and switched to LTE, you can easily burn 500MB in 5 minutes, especially if streaming HD video. When I have a solid LTE connection, the speed tests come back with 85mbps down.

[tsizzle]

You can also check what app or service used the data via your settings (Settings -> Cellular -> Cellular Data Usage section). What Nighthawk suggested is the most likely, also make sure apps that download large updates are set to do so only over WiFi.

[xl]

Switching from wifi to LTE was a painful learning experience for me one night.  I now disable data when I walk into the house to force the phone to use wifi.