Google AJAX Library CDN Versioning

It's amazing what you find when you read the documentation. Since I always forget the address for Google's CDN hosting of jQuery I have to search for it each time. This time when I found the address I was looking around a bit and found out this interesting tidbit that I didn't know before about Google's CDN for their AJAX libraries.

Specifying a version of "1.8.2" will select the obvious version. This is because a fully specified version was used. Specifying a version of "1.8" would select version 1.8.4 since this is the highest versioned release in the 1.8 branch. For much the same reason, a request for "1" will end up loading version 1.9.1.

Google AJAX Libraries API Developer's Guide

For example, if I were linking to jQuery I would normally have used the following and updated semi-regularly:

http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js

But if I just want the latest for the "1.3" version I could reference:

http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js

Or if I was feeling really risky and trust jQuery not to break between minor versions:

http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js

Hope its as useful to others as I found it!

Posted on 10 Dec 2009