Benchmark: getElementById + getElementByClassName vs querySelector

HTML Preparation code:

<div id="testElement">
  <div class="testElementChild"></div>
  <div class="testElementChild"></div>
  <div class="testElementChild"></div>
  <div class="testElementChild"></div>
  <div class="testElementChild"></div>
</div>

Tests:

getElementById + getElementByClass
var el = document.getElementById('testElement'); var children = el.getElementsByClassName('testElementChild'); var length = children.length;
querySelector
var el = document.querySelector('#testElement .testElementChild'); var length = el.length;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById + getElementByClass
querySelector

Fastest: N/A

Slowest: N/A

ⓘ Get performance results from real users on your website with Request Metrics.

Website Performance Monitoring by Request Metrics

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.124 YaBrowser/22.9.3.894 Yowser/2.5 Safari/537.36

Browser/OS: Yandex Browser 22 on Linux

View result in a separate tab

Test name	Executions per second
getElementById + getElementByClass	2050427.0 Ops/sec
querySelector	1899854.0 Ops/sec

getElementById + getElementByClassName vs querySelector (version: 0)

Comparing performance of: getElementById + getElementByClass vs querySelector

Created: 4 years ago by: Guest

Jump to the latest result

getElementById + getElementByClass

querySelector

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A