According to CNN Money many iPhone users have complained about unusually high cell phone bills after upgrading to iOS 9. Wi-Fi Assist is most likely the culprit.
Wi-Fi Assist is a new feature in iOS 9 that toggles your iPhone over to cellular data if you are connected to Wi-Fi and have a weak signal. Chris Mills from Gizmodo shared his experience with Wi-Fi Assist and noticed that his cellular data usage increased from his normal 3GB to 4GB a month.
Apple has enabled the feature by default so if you are on a limited data plan you may want to go ahead and switch Wi-Fi Assist off. To do so..
1. First open the Settings app.
2. Choose the Cellular Data option.
3. Then scroll all the way down to the bottom of the page to find Wi-Fi Assist. Switch the slider to off and you’re all set to binge watch a show on Netflix without the worry of an outrageous bill showing up in the mail next month.
If you are on an unlimited data plan, Wi-Fi Assist is a useful feature. The seamless transition between Wi-Fi and cellular comes in useful when you either leave a Wi-Fi area and move to cellular or if you just have a poor Wi-Fi connection.
In the past I bet that you’ve had a text message fail to send or a podcast cutout for half a block as you left your house to walk your dog. Prior to iOS 9 your iPhone would hold on to that weakening Wi-Fi signal even when it became useless and there was an aggravating lag before it transitioned to cellular data. There were also those situations when you turned off Wi-Fi because of a bad connection only to forget to turn it back on. With iOS 9, Wi-Fi Assist solves those problems.
If you are on a limited data plan, you can still enjoy the usefulness of the feature as long as you monitor your data usage and know how to tell when Wi-Fi Assist has made the switch over to your cellular data. Your iPhone will not notify you when it transitions, but there is one small clue to look for. The Wi-Fi icon at the top of the screen will become grayed out when switched to cellular. When you notice the gray Wi-Fi icon you should probably quit streaming Big Bang Theory and try to find a better Wi-Fi connection.
All four of the major carriers have iPhone apps that will help you monitor your data usage. So if you plan to use the feature and you are on a limited data plan I would suggest downloading and setting up one of these apps if you haven’t already.
When Apple introduces a new useful feature there’s always the risk of negative side effects. Wi-Fi Assist is a helpful addition to iOS but it comes at a price. Maybe a big price if you aren’t careful. If you choose to use the feature be sure to monitor your data and look for the grayed out Wi-Fi icon. Also, if you are streaming content, such as a podcast or a ballgame, be aware of when you leave a Wi-Fi connection.