UITextView is a scrollable, multiline text region and its object : “textContainer” defines where the text will be laid out.
The instance property “textContainerInset” of the text view defines the inset of the text container’s layout area within the text view’s content area
It has a default value of (8, 0, 8, 0)
You can remove those 8 points margins from top or button or add margins to left and right by changing the value of this property
self.txtDemo.textContainerInset = UIEdgeInsetsMake(0, 0, 0, 0)