iOS 9 brought a useful new feature you may not have noticed yet. Known as “Facedown detection”, your iPhone can detect when it’s placed face down and won’t turn the screen on when notifications arrive. This can save a lot of battery power if you regularly receive notifications.
How Facedown Detection Works
While the technology involved is a little more complex, the tip is simple. When you place your iPhone face up on a table, its screen will automatically turn on each time you receive a new notification on your lock screen . You can glance over at the phone to read the notification without even touching it.
If you don’t plan on looking at your iPhone’s notifications as they arrive, just place your screen face down. You’ll still hear notification sounds and your phone will still vibrate. However, when a notification arrives, its screen will remain powered off. This saves battery power.
Prior to iOS 9, your iPhone’s screen actually turned on every time you received a notification even when it was face down. There was no advantage to putting your iPhone face down aside from not seeing the notifications. The screen would keep turning on, using just as much battery power as if you placed the iPhone face up.
Which iPhones Does This Work With?
Like many iOS features, facedown detection doesn’t work on every iPhone. This particular feature works on the iPhone 5s, iPhone 6, iPhone 6 Plus, iPhone 6s, and iPhone 6s Plus, iPhone SE, iPhone 7, and iPhone 7 Plus.
It does not work on the iPhone 5, iPhone 5c, iPhone 4s, and other older iPhones. It also doesn’t work on any iPad or iPod Touch devices.
Facedown detection needs specific hardware because it uses the motion coprocessor, which is also used for your iPhone’s step tracking feature . In fact, it only works if that feature is on. If you head to Settings > Privacy > Motion and Fitness and disable the “Fitness Tracking” feature, facedown detection will stop working and your iPhone will turn on its display every time it receives a notification, even if it’s set face down on a surface.