Run results for: ownerDocument.defaultView vs window.getComputedStyle

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:138.0) Gecko/20100101 Firefox/138.0

Browser: Firefox 138

Operating system: Ubuntu

Device Platform: Desktop

Date tested: one year ago

window.getComputedStyle

4.4M/s

ownerDocument.defaultView

3.2M/s

View exact numbers

Test name	Executions per second
✓ window.getComputedStyle	4,384,484 Ops/sec
ownerDocument.defaultView	3,183,506 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);