Which Javascript minifier (cruncher) does the same things that the one Google uses for its JS APIs?

Question

I am a Google Maps API (javascript) developer. I have noticed that Google uses a Javascript minifier that has the following features:

1. Shortens variables, prope

Answer 1

A simple online javascript minifier based on dojo's shrink safe can be found at http://netspurt.com

Answer 2

What you are describing is an "obfuscator" not a minifier, and they are easily found by searching for "Javascript obfuscator".

Our SD Thicket ECMAScript Obfuscator both obfuscates and minifies at the same time.

Answer 3

There's also a .NET port of YUI Compressor which allows you to:-

• intergrate the minification/file combining into Visual Studio post-build events
• intergrate into a TFS Build (including CI)
• if you wish to just use the dll's in your own code (eg. on the fly minification).

Answer 4

Google has now opened up the minifier they use along with some other internal javascript goodies.

It's all under the name "Closure Tools" and was announced earlier this month.

Answer 5

Here are the minifiers I know of: Dean Edwards' packer; YUI Compressor; JSMIN; and Dojo compressor

In addition to these, the GWT compiler does quite a bit to make efficient JavaScript files out of Java files. It wouldn't surprise me if that is what they use.

Answer 6

I believe that YUICompressor does #1, except for the function names, and #2 using a special syntax that is removed during compression.

#3 is just a build task, not a function of the compressor.

YUICompressor