Letting Google Load jQuery… The Right Way

December 7th, 2009
By: Cory Mathews

For some time now I have been letting google load the jQuery and jQuery UI libraries for me. There are many benefits to it which I will not get into, you can read more reasons to use it elsewhere. However I did notice something worth posting.

You may be loading the jQuery library like so:

<script src="http://jqueryjs.googlecode.com/files/jquery-1.3.2.min.js" type="text/javascript"></script>

Well if you are then you are doing it wrong.

It was ySlow that told me why. Try changing that one line to the following and take another look at ySlow.

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js" type="text/javascript"></script>

Notice the difference? Google is now gzipping the library when its called from googleapis.com instead of googlecode.com thus lowering the files size drastically.

For those of us that are to lazy to try it out here is the result with the googleapis.com loaded instead of the googlecode.com.

jQueryLoading

You can see instead of downloading 57.2kb that you would with the googlecode file the gzip compression brings it down to 19kb.

The same rule would apply for other libraries that are hosted by google. such as mootools, or even the jQuery UI.

So next time you go to include the library make sure to do it the right way.

Now I just need to switch all the sites I have that are using it.. such as this one.