How Big is that Library?

Last weekend I took an old web application that had a Java back-end, a lot of hand-made JavaScript in the client, and a Node server just for websockets and converted everything to an all-JavaScript application to be run via Node.

Along the way I was also switching the JavaScript client library from Dojo to jQuery.

While the process was generally a positive one, I did learn a few things. The one I'll talk about today is the size of the client JavaScript library.

I was surprised to learn that in my case, jQuery was not a smaller client download than Dojo. If you look at their most recent versions, 1.10 for Dojo and 1.11 for jQuery, jQuery is smaller. But I was using a rather old version of Dojo, 1.4.3, which was only 87KB. The current version of jQuery is 94KB.

This got me wondering how large jQuery was back when I first made the app. I decided to perform some analysis just to satisfy my curiosity. Here is what I learned.

jQuery Version	Size (KB)	Release Date
1.11.0	94.1	1-23-2014
1.10.2	90.9	7-3-2013
1.9.1	90.5	2-4-2013
1.8.3	91.4	11-13-2012
1.7.2	92.6	3-21-2012
1.6.4	89.5	9-12-2011
1.5.2	83.9	3-31-2011
1.4.4	76.8	11-11-2010
1.3.2	55.9	2-19-2009
1.2.6	54.5	5-24-2008

Dojo Version	Size (KB)	Release Date
1.10.0	117	6-13-2014
1.9.3	115	2-20-2014
1.8.5	114	6-14-2013
1.7.4	101	10-5-2012
1.6.1	89.6	5-20-2011
1.5.1	88.2	4-12-2011
1.4.5	87.4	8-24-2010
1.3.2	79.6	7-15-2009
1.2.3	76.8	12-8-2008

The sizes I list above are for the minimized code of course. I highlighted the versions of each that were the latest when I originally made the application. At the time, jQuery was smaller but not by an enormous margin. I was more familiar with Dojo at the time, which really drove my decision to use it more than the size of the download.

The other thing I thought was interesting here was how stable jQuery has been in terms of size since 2012. The Dojo Toolkit has jumped all over the place but jQuery has been near 90KB for quite some time. In fact, you have to go back to 2009 to see a really significant change in code size.

As for the changes I had to make in my application when I switched, well, they weren't all that significant. I changed things like

dojo.byId('something')

to

$('#something')

and modified the AJAX calls a little, but there were no really major problems with the conversion. These days I just prefer working with jQuery mainly because I think the syntax is easier to remember and I have a much better experience finding useful information in their online documentation when I'm looking for something. I don't know why more products can't have online documentation as easy to use as jQuery's.

Amphibian.com comic for September 8, 2014