Run results for: ownerDocument.defaultView vs window.getComputedStyle

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 Safari/537.36

Browser: Chrome 88

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
ownerDocument.defaultView	909925.4 Ops/sec
window.getComputedStyle	1201560.0 Ops/sec

HTML Preparation code:

<div id="root"><div>

Script Preparation code:

var el = document.getElementById("root");
function getStyle(elem){
  var view = elem.ownerDocument.defaultView;
  if ( !view || !view.opener ) {
    view = window;
  }

  return view.getComputedStyle( elem );
}

function getStyle2(elem){
  return window.getComputedStyle( elem );
}

Tests:

ownerDocument.defaultView
var computedStyle = getStyle(el);
window.getComputedStyle
var computedStyle = getStyle2(el);