//Check if Safari
function isSafari() {
return /^((?!chrome).)*safari/i.test(navigator.userAgent);
}
//Check if MAC
if(navigator.userAgent.indexOf('Mac')>1){
alert(isSafari());
}
// Safari uses pre-calculated pixels, so use this feature to detect Safari
var canva = document.createElement('canvas');
var ctx = canva.getContext("2d");
var img = ctx.getImageData(0, 0, 1, 1);
var pix = img.data; // byte array, rgba
var isSafari = (pix[3] != 0); // alpha in Safari is not zero