add_action('get_header', 'g3w_html_minify_start');
function g3w_html_minify_start()  {
    ob_start( 'g3w_html_minyfy_finish' );
}
 
function g3w_html_minyfy_finish( $html )  {
 
   //    HTML 
   //      IE
   $html = preg_replace('/<!--(?!s*(?:[if [^]]+]|!|>))(?:(?!-->).)*-->/s', '', $html);
 
   //   
   $html = str_replace(array("\r\n", "\r", "\n", "\t"), '', $html);
   while ( stristr($html, '  ')) 
       $html = str_replace('  ', ' ', $html);
 
   return $html;
}