UILabel default kerning different from CATextLayer

Question

I have a UILabel with the string \'LA\'. I also have a CATextLayer with the same characters in an NSAttributedString assigned to its

Answer 1

UIKit generally uses WebKit for its text rendering (as visible in this crash log), most likely for performance reasons. If you really need super-precision then there are some custom UILabel reimplementations using CoreText as its back-end.

EDIT: As of iOS7 this is no longer true since UILabel uses TextKit for its rendering which is based on CoreText as well.