############################Lazy load for images############################
function add_image_responsive_class($content) {
   $pattern ="/<img\s*(?:class\s*\=\s*[\'\"](.*?)[\'\"].*?\s*|src\s*\=\s*[\'\"](.*?)[\'\"].*?\s*|alt\s*\=\s*[\'\"](.*?)[\'\"].*?\s*|title\s*\=\s*[\'\"](.*?)[\'\"].*?\s*|width\s*\=\s*[\'\"](.*?)[\'\"].*?\s*|height\s*\=\s*[\'\"](.*?)[\'\"].*?\s*)+.*?>/i";
   $replacement = '<img class="$1 lazy" data-src="$2" alt="$3" title="$4" width="$5" height="$6" />';
   $content = preg_replace($pattern, $replacement, $content);
   return $content;
}
add_filter('the_content', 'add_image_responsive_class');
############################Lazy load for images############################