Run results for: DOM traversal

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0

Browser: Firefox 52

Operating system: Ubuntu

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
querySelector	92995.5 Ops/sec
getElementsByClassName	23396560.0 Ops/sec

HTML Preparation code:

<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="bar"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>
<p class="foo"></p>

Tests:

querySelector
document.querySelector('.bar')
getElementsByClassName
document.getElementsByClassName('bar')

Run results for: DOM traversal

Yeah!

querySelector

getElementsByClassName