A button performs an app-specific action. Buttons have customizable backgrounds and rounded corners. They can contain a label, an image, or a group object.

Prefer buttons that span the width of the screen. Full-width buttons look better and are easier to tap. If two buttons must share the same horizontal space, use the same height for both and use images or short text labels for each button’s content.

Use the same height for vertical stacks of one- and two-line text buttons. As much as possible, use identical button heights for visual consistency.

Use the standard corner radius. The standard corner radius for a button is six points. Using the standard radius promotes a consistent visual style across apps and reinforces the intent of buttons.

Make sure buttons that aren't full-width are large enough to be tapped easily. Size buttons according to the following minimum values.

Button type 38mm (minimum) 42mm (minimum)
Circular 75 pixels 80 pixels
Round rectangular 50 pixels high 52 pixels high

For developer guidance, see WKInterfaceButton.