Register/Enqueue Polyfill Scripts in WordPress for Legacy IE

Just add the following code to your functions.php. These are what people call polyfills for Internet Explorer. It will only load these scripts on IE8, so it won’t weigh down those valuable people that have modern browsers 🙂

Make sure to also have this line in your .htaccess file AddType text/x-component .htc

Things you can adjust:

• Serve the js files locally, instead of from a CDN
• Change the conditional to also target IE6-7
• Another useful polyfill: CSS3Pie

  // IE Fixes
  function ie_scripts() {
      // HTML5 elements for IE8
      wp_register_script( 'html5shiv', ( '//cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.3/html5shiv.min.js' ), false, null, true );
      wp_enqueue_script('html5shiv');
      wp_script_add_data( 'html5shiv', 'conditional', 'lt IE 9' );
  
      // Make responsive websites and media queries work in IE8
      wp_register_script( 'respond', ( '//cdnjs.cloudflare.com/ajax/libs/respond.js/1.4.2/respond.min.js' ), false, null, true );
      wp_enqueue_script('repond');
      wp_script_add_data( 'respond', 'conditional', 'lt IE 9' );
  
      // Support for :nth-child(n), :last-child, etc in IE8
      wp_register_script( 'selectivizr', ( '//cdnjs.cloudflare.com/ajax/libs/selectivizr/1.0.2/selectivizr-min.js' ), false, null, true );
      wp_enqueue_script('selectivizr');
      wp_script_add_data( 'selectivizr', 'conditional', 'lt IE 9' );
  
      // Make form placeholders work in IE
      wp_register_script( 'placeholder', ( '//cdnjs.cloudflare.com/ajax/libs/jquery-placeholder/2.3.1/jquery.placeholder.min.js' ), false, null, true );
      wp_enqueue_script('placeholder');
      wp_script_add_data( 'placeholder', 'conditional', 'lt IE 9' );
  }
  add_action( 'wp_enqueue_scripts', 'ie_scripts' );