Apple’s hidden iOS 9 feature that could drain your iPhone’s mobile data

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.