Minimising the time a user has to wait for a web page to load is crucial. Using Gzip and PHP we can minimise file sizes of CSS files. This technique is a powerful and simple way to reduce page download size and speed up your site that will work with most PHP installations, even those on shared hosting that don’t have mod_deflate turned on in their Apache configuration.

Just add the code below at the top of your page. You then need to change the links to point to your CSS files.

  if(extension_loaded('zlib')){
    ob_start('ob_gzhandler');
  }
  header ("content-type: text/css; charset: UTF-8");
  header ("cache-control: must-revalidate");
  $offset = 60 * 60;
  $expire = "expires: " . gmdate ("D, d M Y H:i:s", time() + $offset) . " GMT";
  header ($expire);
  ob_start("compress");
  function compress($buffer) {
      // remove comments
      $buffer = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer);
      return $buffer;
    }

   // list CSS files or JS to be included in the Gzip
    include('global.css');
    include('style.css');

  if(extension_loaded('zlib')){
    ob_end_flush();
  }