iPad version detection in JavaScript

Question

Is it possible to check for the iPad version (1 or 2) in a web application? As the user agent looks identical (see http://www.webtrends.com/Support/KnowledgeBase/SolutionDet

Answer 1

Detect between iPad 1 and 2 Steps:

1. Check UA String for iPad
2. Check for Gyroscope

Detect between iPad 2 and 3 Steps:

1. Check UA String for iPad
2. Check Pixel Density (Retina iPad 3 Displays = 2)

Detect between iPad 3 and 4 Steps:

1. Check UA String for iPad
2. Check Pixel Density (Retina Displays = 2)
3. Check the Devices Maximum Anisotropy (iPad 3 = 2, iPad 4 = 16)

Maximum Anisotropy of 16 usually indicates a modern device with decent graphics performance.

var gl;
var iPadVersion = false;

window.ondevicemotion = function(event) {
  if (!iPadVersion && navigator.platform.indexOf("iPad") != -1) {
    iPadVersion = 1;
    if (event.acceleration) iPadVersion = window.devicePixelRatio;
  }
  window.ondevicemotion = null;
}

function initWebGL(canvas) {
  gl = null;

  try {
    gl = canvas.getContext("webgl") || canvas.getContext("experimental-webgl");
  }
  catch(e) {}

  if (!gl) {
    gl = null;
  }

  return gl;
}

function checkMaxAnisotropy() {
  var max = 0;

  var canvas = document.getElementById('webGLCanvasTest');
  gl = initWebGL(canvas);

  try {
    gl = canvas.getContext("webgl") || canvas.getContext("experimental-webgl");
  }
  catch(e) {}

  if (gl) {
    var ext = (
      gl.getExtension('EXT_texture_filter_anisotropic') ||
      gl.getExtension('MOZ_EXT_texture_filter_anisotropic') ||
      gl.getExtension('WEBKIT_EXT_texture_filter_anisotropic')
    );

    if (ext){
      max = gl.getParameter(ext.MAX_TEXTURE_MAX_ANISOTROPY_EXT);
    }
  }
  return max;
}

function isiPad( $window ) {
  var ua = $window.navigator.userAgent || $window.navigator.vendor || $window.opera;
  return (/iPad/).test(ua);
}


function getiPadVersion( $window ) {
  if(isiPad(window) && window.devicePixelRatio === 2) {
    if(checkMaxAnisotropy() < 4) {
      iPadVersion = 3;
    } else {
      iPadVersion = 4;
    }
  }
  return iPadVersion;
}


/* BONUS CODE 
   isSmartDevice() - Detect most mobile devices
   isOldDevice() - Detect older devices that have poor video card performance
*/

function isSmartDevice( $window ) {
  var ua = $window.navigator.userAgent || $window.navigator.vendor || $window.opera;
  return (/iPhone|iPod|iPad|Silk|Android|BlackBerry|Opera Mini|IEMobile/).test(ua);
}

function isOldDevice() {
  if(isSmartDevice(window) && window.devicePixelRatio === 1 && checkMaxAnisotropy() < 4 || isiPad( window ) && checkMaxAnisotropy() < 4) {
    return true;
  } else {
    return false;
  }
}


alert('iPad Version: ' + getiPadVersion(window) );

#webGLCanvasTest {
  width: 1px;
  height: 1px;
  position: fixed;
  top: -1px;
  left: -1px;
}