While one of Apple's newest iOS 9 features has long been available and known to Android users it is a new feature for those on the iPhone, unfortunately however this also means a slew of new complaints, misunderstanding of its use and issues with the 'always on' status of the feature which has caused many to worry that their data usage will climb out of control.
iOS 9 introduced Apple iPhone users to Wi-Fi Assist a feature that automatically switches between Wi-Fi and mobile data in order to provide users the best connection possible.
"With Wi-Fi Assist, you can stay connected to the Internet even if you have a poor Wi-Fi connection," Apple explains. "For example, if you're using Safari with a poor Wi-Fi connection and a webpage doesn't load, Wi-Fi Assist will activate and automatically switch to cellular so that the webpage continues to load."
As many Android users well know Smart Network Switch, which is what the feature is known as for many Android users, is not without issues and has been known to cause high data consumption in many cases. These issues now appear to be impacting Apple Wi-Fi Assist users as several sites are reporting a surge in complaints over higher than normal data usage.
Users not familiar with the feature weren't aware of its on by default status and had no way of knowing that even though they thought they were using Wi-Fi, Wi-Fi Assist was dropping those connections to connect to mobile data instead. At the heart of the issue, at least from what we have seen on Android devices, is even though it appears as though you have a great Wi-Fi connection the app may still drop one service over the other, favoring the stability of mobile data in many cases over inconsistent Wi-Fi connections.
Looking to ease some concerns over the growing number of complaints, and many articles calling on users to disable the new features, Apple this week updated its About Wi-Fi Assist page to provide users more details as to how the feature should behave. Apple specify wanted to note that the feature will not automatically switch to cellular if you're data roaming. It only works when you have apps running in the foreground, and won't activate with content downloading in the background. Apple also noted that Wi-Fi Assist won't (or shouldn't) activate with certain data-hogging, third-party apps. That includes apps that stream audio or video or download attachments, like email services.
For users concerned over how Wi-Fi Assist might be impacting their data usage there are a couple options. The easiest would be to simply turn it off via Settings > Cellular. Towards the bottom of the page, you'll find the Wi-Fi Assist switch; just toggle it off. Another more involved option would to restrict each app and their permission to use cellular data. That access can be revoked on the same Settings screen where you access Wi-Fi Assist. (There's been some discussion of this in Apple Support Communities.)