Add Random Sorting to WooCommerce Catalog

The following code is an example of how to add a random sorting option on the WooCommerce product catalog page. In the same way you can add any sorting option you want according to the options available for the orderby parameter of WP_Query. Take a look at the WordPress Codex for more information about the orderby parameter.

This code should be in your functions.php file:

/**
 * Add custom sorting options (asc/desc)
 */
add_filter( 'woocommerce_get_catalog_ordering_args', 'custom_woocommerce_get_catalog_ordering_args' );
function custom_woocommerce_get_catalog_ordering_args( $args ) {
  $orderby_value = isset( $_GET['orderby'] ) ? wc_clean( $_GET['orderby'] ) : apply_filters( 'woocommerce_default_catalog_orderby', get_option( 'woocommerce_default_catalog_orderby' ) );
	if ( 'random_list' == $orderby_value ) {
		$args['orderby'] = 'rand';
		$args['order'] = '';
		$args['meta_key'] = '';
	}
	return $args;
}
add_filter( 'woocommerce_default_catalog_orderby_options', 'custom_woocommerce_catalog_orderby' );
add_filter( 'woocommerce_catalog_orderby', 'custom_woocommerce_catalog_orderby' );
function custom_woocommerce_catalog_orderby( $sortby ) {
	$sortby['random_list'] = 'Random';
	return $sortby;
}

For more on WooCommerce product queries, see Properly Retrieve WooCommerce Products.