Learn what to do if your iPhone keeps disconnecting itself from a Wi-Fi network and starts using cellular data instead.
How to stop your iPhone from auto-switching from Wi-Fi to cellular data
Wi-Fi Assist
New in iOS 9.3 beta 1: Wi-Fi Assist usage statistics
It's now easier than ever to keep an eye on how much data is used by Wi-Fi assist, thanks to a new data monitor found in iOS 9.3 beta 1. Wi-Fi assist, is the controversial feature that taps into your iPhone's cellular connection in those instances where the Wi-Fi connection may not be adequate enough.
First noted by MacRumors' Juli Clover, the addition of data usage numbers for Wi-Fi Assist will help those who claim to have experienced exorbitant amounts of cellular data usage due to the feature.
iOS 9’s Wi-Fi Assist, fully explained and demystified
Wi-Fi Assist, a new feature in iOS 9, was initially met with some skepticism as Apple did a lousy job detailing how it works beyond stating that Wi-Fi Assist automatically uses cellular data when Wi-Fi connectivity is poor.
“With Wi-Fi Assist, you can stay connected to the Internet even if you have a poor Wi-Fi connection,” the iPhone maker said somewhat critically.
However, inexperienced users might encounter some unwanted effects when using their devices in areas with low Wi-Fi signal because Wi-Fi Assist will activate their carrier's mobile data network and therefore possibly lead to increased data consumption and unwanted overage fees on the wireless bill.
Here's what Apple is saying how Wi-Fi exactly works.
If iOS 9 is gobbling up all your mobile data, you should turn Wi-Fi Assist off
iOS 9 includes a new feature designed to optimize network performance by automatically switching to a mobile data network if a poor Wi-Fi signal is detected or Wi-Fi responds painfully too slow. It's called Wi-Fi Assist and comes enabled by default on iPhones and cellular iPads running iOS 9 or iOS 9.0.1.
As first noted by Quartz, some iPhone owners with poor Wi-Fi reception are seeing dramatic increases in their mobile data usage after updating to iOS 9.
For example, some folks are reporting a jump from one to as much as seven gigabytes since updating to iOS 9. To avoid unwanted overage fees on your wireless bill, disable Wi-Fi Assist with just a few taps, here's how.
What is Wi-Fi Assist and how to use it on your iPhone
Learn about what Wi-Fi Assist on your iPhone and cellular iPad is and how to use it to ensure you never have internet downtime, even if your Wi-Fi connection is weak.