Run results for: querySelector vs getElementById vs getElementsByClassName vs getElementsByTagName

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Safari/537.36

Browser: Chrome 92

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
getElementById	3273564.2 Ops/sec
querySelector (id)	1465182.4 Ops/sec
getElementsByClassName	3346684.5 Ops/sec
querySelector (class)	2381904.8 Ops/sec
getElementsByTagName	3377794.5 Ops/sec
querySelector (tag)	2317610.2 Ops/sec

HTML Preparation code:

    <div class="test1">
        <div class="test1">
        <div class="test1"></div>
        <div class="test1"></div>
        <div class="test1">
            <div class="test1">
                <div class="test1"></div>
            </div>
        </div>
        <div class="test1"></div>
        <div class="test1"></div>
        </div>
        <div class="test1">
        <div class="test1"></div>
        <div class="test1">
            <div class="test1">
                <div class="test1"></div>
            </div>
        </div>
        <div class="test1">
            <div class="test1">
                <div class="test1"></div>
            </div>
        </div>
        <div class="test1"></div>
        </div>
        <div class="test1"></div>
        <div class="test1">
        <div class="test1"></div>
        <div class="test1">
            <div class="test1">
                <div class="test1"></div>
            </div>
            <div class="test1"></div>
        </div>
        <div class="test1"></div>
        <div class="test1"></div>
        <div class="test1"></div>
        </div>
        <div class="test1"></div>
        <div class="test1">
        <div class="test1">
            <div class="test1"></div>
            <div class="test1">
                <div class="test1">
                    <div class="test1">
                    <article class="test" id="test"></article>
                    </div>
                    <div class="test1">
                    <div class="test1"></div>
                    </div>
                    <div class="test1"></div>
                </div>
                <div class="test1"></div>
            </div>
        </div>
        <div class="test1"></div>
        <div class="test1"></div>
        </div>
        <div class="test1">
        <div class="test1"></div>
        <div class="test1">
            <div class="test1"></div>
            <div class="test1"></div>
        </div>
        <div class="test1"></div>
        <div class="test1"></div>
        <div class="test1"></div>
        </div>
    </div>

Tests:

getElementById
document.getElementById("test");
querySelector (id)
document.querySelector("#test")
getElementsByClassName
document.getElementsByClassName("test")
querySelector (class)
document.querySelector(".test")
getElementsByTagName
document.getElementsByTagName("test")
querySelector (tag)
document.querySelector("article")

Run results for: querySelector vs getElementById vs getElementsByClassName vs getElementsByTagName

getElementById

querySelector (id)

getElementsByClassName

querySelector (class)

getElementsByTagName

querySelector (tag)