Check if element is visible (in viewport(

jquery-visible.js

(function($) {

  $.fn.visible = function(partial, hidden) {

    var $t = $(this).eq(0),
      t = $t.get(0),
      $w = $(window),
      viewTop = $w.scrollTop(),
      viewBottom = viewTop + $w.height(),
      _top = $t.offset().top,
      _bottom = _top + $t.height(),
      compareTop = partial === true ? _bottom : _top,
      compareBottom = partial === true ? _top : _bottom,
      clientSize = hidden === true ? t.offsetWidth * t.offsetHeight : true;

    return !!clientSize && ((compareBottom <= viewBottom) && (compareTop >= viewTop));
  };

})(jQuery);

/*
    if( $('.el').visible(true) ) {
        //your code here
    }
*/