Efficient stylesheet minification in C#

Published Feb 28, 2010

A few weeks back i found out that the method I use to minify CSS was about 5% more efficient than the YUI Compressor. I tweeted about it and was encouraged to post the code that does the actual minification.

public static string RemoveWhiteSpaceFromStylesheets(string body)
{
  body = Regex.Replace(body, @"[a-zA-Z]+#", "#");
  body = Regex.Replace(body, @"[\n\r]+\s*", string.Empty);
  body = Regex.Replace(body, @"\s+", " ");
  body = Regex.Replace(body, @"\s?([:,;{}])\s?", "$1");
  body = body.Replace(";}", "}");
  body = Regex.Replace(body, @"([\s:]0)(px|pt|%|em)", "$1");
 
  // Remove comments from CSS
  body = Regex.Replace(body, @"/\*[\d\D]*?\*/", string.Empty);
 
  return body;
}

The method takes a string of CSS and returns a minified version of it. The method have been modified for demo purposes, so you might want to optimize the code yourself.

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