getElementById vs. querySelector

JavaScript performance comparison

Revision 11 of this test case created

Info

Compare the speed of getElementById to querySelector

Preparation code

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

Foo

Bar

Baz

Test runner

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

Java applet disabled.

Testing in unknown unknown
Test Ops/sec
getElementById
var bar = document.getElementById("bar");
pending…
querySelector
var bar = document.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. Here’s a list of current revisions for this page:

0 comments

Add a comment