This Video explains how to crop videos on iPhone, iPod touch, and iPad devices with iOS 11 or later. Instructions include how to use the built-in crop feature on iOS devices and how to use a third-party cropping app, which is needed to crop videos on any device with iOS 12 or earlier.
Summery:
Open the Photos app.
Navigate to and select the video you would like to crop.
Select Edit.
Select the Crop button, indicated by a square with circling arrows in the menu at the bottom of the screen.
Use the handles on the edges of the video to reshape the canvas so that the unwanted areas are shaded out.
Select Done to save your changes.
#Iphone