maxTouchPoints

Summary

The maximum number of simultaneous touch contacts supported by the device.

Syntax

Note: This property is read-only.

var result = navigator.maxTouchPoints;

Return Value

Returns an object of type NumberNumber

Examples

Basic HTML5 Canvas painting application

<style>
  /* Disable intrinsic user agent touch behaviors (such as panning or zooming) so
  that all events are given to the application instead. */

  html {
    touch-action: none;
  }
</style>

<canvas id="drawSurface" width="500px" height="500px" style="border:1px solid black;"></canvas>

<script type='text/javascript'>
window.addEventListener('load', function() {
  var canvas = document.getElementById("drawSurface"),
  context = canvas.getContext("2d");
  if (window.navigator.pointerEnabled) {
    canvas.addEventListener("pointermove", paint, false);
    if(window.navigator.maxTouchPoints>1)
        alert("Your user agent and hardware support multi-touch!");
  }
  else {
    //Provide fallback for user agents that do not support Pointer Events
    canvas.addEventListener("mousemove", paint, false);
  }
  function paint(event) {
    if(event.buttons>0)
        context.fillRect(event.clientX, event.clientY, 5, 5);
  }
});

Usage

 In the case of devices with multiple digitizers (e.g. multiple touchscreens), the value must be the maximum of the set of maximum supported contacts by each individual digitizer.

For example, suppose a device has 3 touchscreens, which support 2, 5, and 10 simultaneous touch contacts, respectively. The value of maxTouchPoints is 10.

Related specifications

Pointer Events: Working Draft

Attributions

Microsoft Developer Network: [maxTouchPoints property Article]