Defer certain WordPress scripts

gistfile1.txt

/**
 * Add 'defer' to certain scripts, dependant on their handle
 */
function fdFS2d_theme_make_script_defer( $tag, $handle, $src ) {


    $script_handles = array(
        'wplc-server-script',
        'wplc-user-script',
        'wplc-md5',
        'wplc-node-server-script',
        'wplc-user-js-emoji-concat',
        'wplc-user-events-script',
        'wplc-theme-modern',
        'wplc-user-pro-editor',
        'wplc-user-pro-events-script',
        'wplc-user-pro-features',
        'wplc-user-jquery-cookie',
        'bleeper-action-script',
    );
    if ( in_array( $handle, $script_handles ) ) {
        return str_replace( '<script', '<script defer', $tag );
    }

    // Just return the default tag if we didnt get a match above
    return $tag;
}
add_filter( 'script_loader_tag', 'fdFS2d_theme_make_script_defer', 10, 3 );