WP Optimization

<?php

/***required plugins**/
//W3 Total Cache: https://wordpress.org/plugins/w3-total-cache/
//Async JS and CSS: https://wordpress.org/plugins/async-js-and-css/
//EWWW Image Optimizer: https://wordpress.org/plugins/ewww-image-optimizer/
//Above The Fold Optimization: https://wordpress.org/plugins/above-the-fold-optimization/installation/
//Autoptimize: https://wordpress.org/plugins/autoptimize/
//try out best combination

//php code for functions.php
// Defer jQuery Parsing using the HTML5 defer property
if (!(is_admin() )) {
    function defer_parsing_of_js ( $url ) {
        if ( FALSE === strpos( $url, '.js' ) ) return $url;
        if ( strpos( $url, 'jquery.js' ) ) return $url;
        // return "$url' defer ";
        return "$url' defer onload='";
    }
    add_filter( 'clean_url', 'defer_parsing_of_js', 11, 1 );
}