Run results for: querySelector vs getElementsByClassName (get first element)

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:65.0) Gecko/20100101 Firefox/65.0

Browser: Firefox 65

Operating system: Windows 7

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
querySelector	2030734.0 Ops/sec
getElementsByClassName (first element of)	1752078.0 Ops/sec
getElementById	1997859.0 Ops/sec

HTML Preparation code:

<div id="test" class="test"></div>

Tests:

querySelector
document.querySelector(".test")
getElementsByClassName (first element of)
document.getElementsByClassName(".test")[0]
getElementById
document.getElementById("test")