getElementById vs. querySelector

JavaScript performance comparison

Revision 222 of this test case created by ed

Preparation code

<div id="base">
<p id="foo">Foo</p>
<p id="bar">Bar</p>
<p id="baz">Baz</p>
</base>
      
<script>
Benchmark.prototype.setup = function() {
  var idSelectorRegexp = /^#[a-zA-Z]+[a-zA-Z0-9_\-]*$/;
  
  var select = function(query){
    // pure ID selector?
    if (idSelectorRegexp.test(query))
      return document.getElementById(query.slice(1));
    else
      return document.querySelector(query);
  };

};
</script>

Preparation code output

<div id="base"> <p id="foo">Foo</p> <p id="bar">Bar</p> <p id="baz">Baz</p> </base>

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
getElementById
var bar = document.getElementById("bar");
pending…
querySelector
var base = document.getElementById('base');
var bar = base.querySelector("#bar");
pending…
mapping to getElementById
var bar = select("#bar");
pending…

Compare results of other browsers

Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL.

0 Comments

Foo

Bar

Baz