Run results for: querySelector vs getElementById

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36

Browser: Chrome 53

Operating system: Mac OS X 10.10.3

Device Platform: Other

Date tested: 8 years ago

Test name	Executions per second
querySelector	522717.7 Ops/sec
getElementsByClassName	3318935.8 Ops/sec

HTML Preparation code:

<html>
  <body>
    <div class="foo" id="test2"></div>
    <div class="foo2" id="test"></div>
  </body>
</html>

AخA
 
<html>
  <body>
    <div class="foo" id="test2"></div>
    <div class="foo2" id="test"></div>
  </body>
</html>

Tests:

querySelector
document.querySelector(".foo");
document.querySelector(".foo");
getElementsByClassName
document.getElementsByClassName('foo');
document.getElementsByClassName('foo');