How to remove border of the navigationBar in swift?

The trouble is with these two lines:

self.navigationController?.navigationBar.setBackgroundImage(UIImage(named: ""), forBarMetrics: UIBarMetrics.Default)self.navigationController?.navigationBar.shadowImage = UIImage(named: "")

Since you don't have an image with no name, UIImage(named: "") returns nil, which means the default behavior kicks in:

When non-nil, a custom shadow image to show instead of the default shadow image. For a custom shadow to be shown, a custom background image must also be set with -setBackgroundImage:forBarMetrics: (if the default background image is used, the default shadow image will be used).

You need a truly empty image, so just initialize with UIImage():

self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: UIBarMetrics.default)self.navigationController?.navigationBar.shadowImage = UIImage()

Swift 4 & Swift 5

Removing border:

self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for:.default)self.navigationController?.navigationBar.shadowImage = UIImage()self.navigationController?.navigationBar.layoutIfNeeded()

Restoring border:

self.navigationController?.navigationBar.setBackgroundImage(nil, for:.default)self.navigationController?.navigationBar.shadowImage = nilself.navigationController?.navigationBar.layoutIfNeeded()

With Swift 2 you can do it this way:

AppDelegate file

Inside func application(..., didFinishLaunchingWithOptions launchOptions:...)

UINavigationBar.appearance().shadowImage = UIImage()UINavigationBar.appearance().setBackgroundImage(UIImage(), forBarMetrics: .Default)

for Swift 3:

UINavigationBar.appearance().shadowImage = UIImage()UINavigationBar.appearance().setBackgroundImage(UIImage(), for: .default)