CSSqueeze: Efficient CSS minification in PHP

CSSqueeze …

It's a single PHP class licensed under Apache 2 and GPLv2.

PHP

• PHP 5.3
• PHP 5.4
• PHP 5.5
• PHP 5.6

Features

• Remove white space and extra characters
• whitespace
• Last semicolon in a statement
• Measurement units for the values (eg margin: 0px -> margin: 0)
• Comments (preserving /*! important comments */)
• Empty statements (eg p {})
• Use shorthand properties
  • margin
  • padding
  • border
  • outline
  • list-style
  • background (eg instead of background-color)
• Compress colors
  • Use short notations of hexadecimal colors (Ex: color: # ff6600 becomes color: # f60;). Use colors supported in CSS 2 whose name is shorter than the hexadecimal.
• Sorting CSS properties
• Merge properties
• merge rules if required
• @import CSS only if file exists
• @media queries CSS

Compare few minifiers

ranking is by after compression and gzipped, after compression

file compressed : 002/002.css from csszengarden.com

	origin	after compression	saved	compression ratio	after compression and gzipped	compression and gzip ratio
CSSqueeze	5547	2862	2685	48,40%	919	83,43%
csscompressor	5547	2863	2684	48,39%	920	83,41%
YUI	5547	2902	2645	47,68%	920	83,41%
excssive.com	5547	2861	2686	48,42%	924	83,34%
cssminifier.com	5547	2875	2672	48,17%	925	83,32%
cssdrive.com	5547	2964	2583	46,57%	934	83,16%
minifycss.com	5547	2894	2653	47,83%	936	83,13%

Todo

• embed image and/or sprites background-image
• Add vendor prefix
• More shorthands
• rgba(
• change hack throught html class

Vendors Prefix

• -o- Opera
• -moz- Gecko (Mozilla)
• -webkit- Webkit (Chrome, Safari, Android...)
• -ms-/mso- (Internet Explorer)
• -khtml- KHTML (Konqueror)