Preload Fonts

// Preload Newsmag fonts for responsive theme - main theme
function dns_prefetch_responsive() {
    echo "<link href='https://yoursite.com/wp-content/themes/Newsmag/images/icons/newsmag.woff?17' rel='preload' as='font' type='font/woff' crossorigin>";
}
add_action( 'wp_head', 'dns_prefetch_responsive', 0 );

add_filter( 'wp_get_attachment_image_attributes', 'add_fetch_priority_to_featured_image', 10, 3 );
function add_fetch_priority_to_featured_image( $attr, $attachment, $size ) {
    if ( is_single() && 'post-thumbnail' === $size ) {
        $attr['fetchpriority'] = 'high';
    }
    return $attr;
}