Version: 2017.1
public static bool fullScreen ;

Description

Is the game running fullscreen?

It is possible to toggle fullscreen mode by changing this property:

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { void Example() { Screen.fullScreen = !Screen.fullScreen; } }

A fullscreen switch does not happen immediately; it will actually happen when the current frame is finished.

See Also: SetResolution.