yasco is yet another source code obfuscator.

The project’s former name was Yaso (yet another script obfuscator) but since that name was already taken on Google Code, I decided to rename it.

It is entirely written in Perl and makes use of the Parse::Yapp CPAN module by Francois Desarmenien to generate the parser.

yasco can be used to minify Javascript code or additionally obfuscate it. It supports automatic semicolon insertion and soon inline function optimization.


yasco is currently hosted on Google Code.

You can check out the current trunk from:


What it can do

  • perform a syntax check on your code
  • strip comments from your code
  • minimize your code by shortening variable names
  • minimize your code by shortening function names
  • substitute string literals into an encrypted string table
  • make “hashes” unreadable

What it cannot do

  • Make your code unreadable. *

* There’s always a way to “unobfuscate” whatever you feed to any source code obfuscator. It’s Javascript’s nature to be executed on the client side. Even the compressed output is eventually being fed to eval() which anyone can substitute to document.write() and output the code. Still only in one line, but that’s why I invented the -C option. 😉

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