Your iPhone’s screen can rotate based on how you are holding it. This happens automatically, as the iPhone is able to sense whether you are holding the device in portrait or landscape mode.
However, you might find that the rotation is no longer happening, which is making it difficult for you to use the iPhone in the manner to which you are accustomed. Fortunately this can be resolved by turning off a setting in the Control Center, which is a menu that you access by swiping up from the bottom of the screen.
The steps below were performed on an iPhone 7 Plus in iOS 10.2, but will work for other iPhone models running iOS 7 or higher.
Step 1: Swipe up from the bottom of the screen.
Step 2: Tap the lock icon at the top-right corner of the Control Center to turn off Portrait Orientation Lock.
Note that some apps can only be viewed in one orientation. If you have turned off Portrait Orientation Lock and an app still won’t rotate, then it is likely a setting in that app, rather than one on your iPhone.
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