Run results for: clientHeight vs offsetHeight vs window.getComputedStyle

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:77.0) Gecko/20100101 Firefox/77.0

Browser: Firefox 77

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
clientHeight	2661009.0 Ops/sec
offsetHeight	2610278.0 Ops/sec
window.getComputedStyle	1498994.0 Ops/sec
Multiple: Only _style	597761.5 Ops/sec
Multiple: _style e clientHeight	653860.3 Ops/sec

HTML Preparation code:

<div id="teste">teste</div>

Script Preparation code:

var teste_n = '123px';
var _style = window.getComputedStyle(document.getElementById('teste'));

Tests:

clientHeight
document.getElementById('teste').clientHeight;
offsetHeight
document.getElementById('teste').offsetHeight;
window.getComputedStyle
parseFloat(_style['height'])
Multiple: Only _style
parseFloat(_style['margin-top']) parseFloat(_style['margin-bottom']) parseFloat(_style['height'])
Multiple: _style e clientHeight
parseFloat(_style['margin-top']) parseFloat(_style['margin-bottom']) document.getElementById('teste').clientHeight;