`document.head`

JavaScript performance comparison

Test case created by Mathias Bynens on 31st July 2010 and last updated on 28th June 2011

Info

How much faster is the HTML5 document.head DOM tree accessor compared to its old-school variant, document.getElementsByTagName('head')[0]?

Preparation code

<script>
  document.head || (document.head = document.getElementsByTagName('head')[0]);
  
  var headList = document.getElementsByTagName('head');
</script>

Test runner

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Testing in unknown unknown
Test		Ops/sec
`document.getElementsByTagName('head')[0]`	`document.getElementsByTagName('head')[0];`	pending…
`document.head`	`document.head;`	pending…
`querySelector`	`document.querySelector('head');`	pending…
Live nodeList	`headList[0];`	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:

Revision 1: published by Mathias Bynens on 31st July 2010 and last updated on 28th June 2011
Revision 2: published by Charles Lehner on 3rd August 2010
Revision 3: published by kangax on 11th August 2010 and last updated on 24th January 2011
Revision 4: published by stefaan on 28th February 2011
Revision 5: published on 27th October 2011
Revision 6: published on 30th October 2011

2 comments

David McCormack commented on 10th December 2010: ∞

If this test is run on a browser which doesn’t support document.head then doesn’t it just use document.getElementsByTagName('head')[0] anyway which makes the results a bit meaningless?

Mathias Bynens (revision owner) commented on 24th January 2011: ∞

@David: It’s either that or failing the test in those browsers. This test only makes sense in browsers that support document.head.

document.head