The maxTouchPoints read-only property of the Navigator interface returns the maximum number of simultaneous touch contact points that are supported by the current device.
A number.
This value is hardware-dependent. Desktop computers without a touchscreen (Mac, Windows and Linux) return 0 while smartphones (Android and iOS) typically return 5.
if (navigator.maxTouchPoints > 1) {
// Device supports tracking at least 2 touch points; offer complex
// interaction gestures such as swiping with two/three fingers
} else {
// Device only has 1 touch point or is not a touch screen.
// Offer basic gestures such as dragging and clicking
}