Run results for: queryselector (from document or from parent) vs getelementbyid

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:146.0) Gecko/20100101 Firefox/146.0

Browser: Firefox 146

Operating system: Linux

Device Platform: Desktop

Date tested: 7 months ago

parent.querySelector

21.9M/s

document.getElementById

12.2M/s

document.querySelector

5.2M/s

View exact numbers

Test name	Executions per second
✓ parent.querySelector	21,873,652 Ops/sec
document.getElementById	12,219,409 Ops/sec
document.querySelector	5,243,802 Ops/sec

HTML Preparation code:

<div id='abc'>
    <div id='abcd'>
        <div id='abcde'>
            <div id='abcdefg'>
                <div id='abcdefghi'>
                </div>
            </div>
        </div>
    </div>
</div>
<div id='abcdef'>
    <div id='abcdefgh'>
    </div>
</div>

Script Preparation code:

const parent = document.getElementById('abcdefg');

Tests:

document.querySelector
document.querySelector('#abcdefghi');
parent.querySelector
parent.querySelector('#abcdefghi');
document.getElementById
document.getElementById('abcdefghi');