Run results for: getElementById vs getElementsByClassName

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3843.0 Safari/537.36 Edg/77.0.218.4

Browser: Chrome 77

Operating system: Mac OS X 10.14.5

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
getElementById.childNodes	2756750.0 Ops/sec
getElementById.getElementsByTagName	2494184.0 Ops/sec
getElementsByTagName	2844323.0 Ops/sec

HTML Preparation code:

<div id="header">
		<div id="logo">
			<img src="images/logo.png" alt="the network"/>
		</div>	
		<div id="search">
			<form method="get">
				<input type="text" name="post" placeholder="thoughts?"/>
				<input type="submit" value="Post">
			</form>
		</div>
	</div>
</div>

Tests:

getElementById.childNodes
var form = document.getElementById("search").childNodes[0];
getElementById.getElementsByTagName
var form = document.getElementById("search").getElementsByTagName("form")[0];
getElementsByTagName
var form = document.getElementsByTagName("form")[0];

Run results for: getElementById vs getElementsByClassName

getElementById vs getElementsByClassName

getElementById.childNodes

getElementById.getElementsByTagName

getElementsByTagName