How to detect the screen DPI using JavaScript

The only way I found till now, is getting the offsetWidth, offsetHeight of a test div element with height and width of one inch: http://www.infobyip.com/detectmonitordpi.php

Is there a way to detect the screen DPI via JavaScript instead?

Thanks,

Atara.

Answer

<div id='testdiv' style='height: 1in; left: -100%; position: absolute; top: -100%; width: 1in;'></div>
<script type='text/javascript'>
    dpi_x = document.getElementById('testdiv').offsetWidth;
    dpi_y = document.getElementById('testdiv').offsetHeight;
</script>

Then you can use JQuery to send dpi_x and dpi_y this to to your server

http://jsfiddle.net/sxfv3/