iPhone users who keep a close eye on how much mobile data they use may be caught out by a hidden feature in the new iOS 9 update that taps into that vital data pool even when they’re on wi-fi.
Wi-Fi Assist is switched on by default in iOS 9 and is designed to revert to the cellular network automatically if you’re connected to a slow wireless network.
Apple’s intention here is to make your experience faster by tapping into the fastest network that’s available.
But downside of that scenario is that a user may get caught out while they think they’re on a wi-fi network and not using their valuable mobile data.
If that wi-fi connection is slower than your 4G connection, Wi-Fi Assist will switch users to the cellular network and, by doing that, dip into your mobile data supply.
A similar feature can be found on Samsung’s Android-powered phones called Download Booster and users have to opt in to switch it on.
The good news for iOS 9 users who don’t have huge data allowances is that Wi-Fi Assist can be switched off.
Simply go to the Settings > Cellular > then scroll right to the bottom of this screen and you’ll see Wi-Fi Assist which can then be turned off.