getElementById and querySelector VS named element

JavaScript performance comparison

Revision 14 of this test case created by Nonlinearcode


This test shows the performance difference between getting the reference to a DOM element by calling getElementById, querySelector and accessing it via the named element of window.

The test only uses one HTML element with the id as the standard expects to only have one unique element with that ID in the DOM. Other than that the created object "node" will contain a collection if we use querySelector or the named element.

Preparation code

<div id="testid"></div>

Preparation code output

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Test Ops/sec
node = document.getElementById('testid');
node = document.querySelector('#testid');
named elements
node = window.testid;

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1 comment

Nonlinearcode (revision owner) commented :

Revision14 used for testing the performance difference between using the named elements, defined by the HTML Standard, and the other methods.

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