This is a web interface to compress your JavaScript or CSS. This tool uses YUI Compressor 2.4.8.

Warning! This site will soon be replaced by a similar tool I've created which you can test here: It does not use YUI Compressor, but supports many of the newer CSS features.
Paste a block of CSS or JS to compress in the area below.
Choose one or more files of the same type to compress.
Enter one or more URLs of the same type to compress.

Further Reading

In my investigation, I discovered coding patterns that prevented YUI Compressor from performing variable name replacement. By modifying or avoiding these coding patterns, you can improve the YUI Compressor’s performance.

Better JavaScript Minification

Running your JavaScript code through YUI Compressor results in tremendous savings by default, but there are things you can do to increase the byte savings even further.

Helping the YUI Compressor

A minifier removes the comments and unnecessary whitespace from a program. Depending on how the program is written, this can reduce the size by about half. An obfuscator also minifies, but it will also make modifications to the program, changing the names of variables, functions, and members, making the program much harder to understand, and further reducing its size in the bargain.

Minification vs Obfuscation

When we talk of style here, we are not talking about fads and fashions, nor are we talking about CSS or conventions of layout or typography. We are talking about timeless qualities of expression which can substantially increase the value of a codebase. For companies whose valuations are are inextricably bound to their codebases, style should be a vital concern.

The Elements of JavaScript Style [ Part 1 | Part 2 ]

A note on Privacy

Every bit of code entered into this tool is made into a file on my server. That file is fed into the YUI Compressor which outputs a compressed version of that file. The original code is removed immediately from the server, but the compressed file sticks around for a while so you can download it. Every hour, files older than 60 minutes are removed automatically from the server.

I made my php class public a while ago. You can see what’s going on here:

I don’t read or copy any of your code. You’ll just have to take my word for it I guess.


May 18, 2012
  • changed to YUI Compressor 2.4.8
February 23, 2012
  • Concat JS
  • Fix CSS linebreak option
February 18, 2012
  • Use Twitter Bootstrap for UI
  • Remember options using localStorage
  • Use name of uploaded/linked file in download name.
November 28, 2011
  • changed to YUI Compressor 2.4.7
June 13, 2011
  • added gzip download option
April 29, 2011
  • changed to YUI compressor 2.4.6
  • fixed character encoding on download link
  • added label for redirect link
March 6, 2011
  • Added option to add file by URL.
February 28, 2011
  • Finally wrote that cron job to purge old files.
October 25, 2010
  • Escape output of input.
October 6, 2010
  • Added the multiple attribute to the file input field
September 3, 2010
  • changed to YUI compressor 2.4.4
April 22, 2010
  • Use the php class I wrote for the yui compressor.
  • Privacy 'policy'
December 13, 2009
  • Download compressed file.
May 30, 2009
  • jump to output after compression
  • upload multiple files
March 10, 2009
  • fix multi-byte character handling. (thanks Alex)
January 18, 2009
  • changed to YUI compressor 2.4.2
  • added line-break option
  • added verbose option
November 7, 2008
  • changed to YUI Compressor 2.4.1
  • added some links to further reading
  • fixed utf-8 encoding
October 7, 2008
  • valid HTML markup for kicks
October 4, 2008
  • added error reporting
  • escape compressed code
October 2, 2008
  • changed to YUI Compressor 2.3.6
  • stopped escaping double quotes
  • hide command