Detect active ad blockers

[da2x]

Active ad blocker (class blocker) detection:

var active_blocker_detected = false,
    test = document.createElement('div');
test.innerHTML=' ';
test.className='adsbox';
document.body.appendChild(test);
window.setTimeout(
  function() {
    active_blocker_detected = (test.offsetHeight == 0);
    test.parentNode.removeChild(test);
}, 250);

Separate category of ad blockers (including AdBlock Plus) from those that only block hosts or by URL (Firefox private window, Firefox Focus, Opera content blocker, Safari mobile extension based blockers, Privacy Badger, etc.).