JS Includes

1. Remove all js file includes from header and put them in functions.php file.
2. Use enqueue function to enque the js in header or footer depending on the requirement. Most of the js should be enqueued in footer for optimization purposes.
3. Dequeue not required js files, default theme js files etc in the beginning of the projects, later on it becomes harder to remove these.

Helpful resources and functions – Inspect all enqueued scripts , Dequeue script on priority

Below is the example of enqueue and dequeue based on front page 

function enqueue_scripts() {


	if( is_front_page() )
    {	
    	//dequeue
    	wp_dequeue_script('sb-core');
    	wp_dequeue_script('twentysixteen-skip-link-focus-fix');
    	wp_dequeue_script('kc-front-scripts');


    	//enqueue
        wp_enqueue_script( 'swiper', get_template_directory_uri() . '/js/swiper.min.js', array(), '1.0', true );
        wp_enqueue_script( 'browser_detect', get_template_directory_uri() . '/js/browser-detect.js', array(), '1.0', true );
        wp_enqueue_script( 'typed-js', get_template_directory_uri() . '/js/typed.min.js', array(), '1.0', true );
        wp_enqueue_script( 'site_functions', get_template_directory_uri() . '/js/site_functions.js', array(), '1.0', true );
        wp_enqueue_script( 'matchheight', get_template_directory_uri() . '/js/jquery.matchHeight.js', array(), '1.0', true );

    }

    if( !is_front_page() )
    {

		wp_enqueue_script( 'swiper', get_template_directory_uri() . '/js/swiper.min.js', array(), '1.0', true );
		wp_enqueue_script( 'browser_detect', get_template_directory_uri() . '/js/browser-detect.js', array(), '1.0', true );
		wp_enqueue_script( 'owl-js', get_template_directory_uri() . '/js/owl.carousel.min.js', array(), '1.0', true );
		wp_enqueue_script( 'typed-js', get_template_directory_uri() . '/js/typed.min.js', array(), '1.0', true );

		wp_enqueue_script( 'wow-js', get_template_directory_uri() . '/js/wow.min.js', array(), '1.0', true );
		wp_enqueue_script( 'matchheight', get_template_directory_uri() . '/js/jquery.matchHeight.js', array(), '1.0', true );
		wp_enqueue_script( 'fancybox-js', get_template_directory_uri() . '/js/jquery.fancybox.min.js', array(), '1.0', true );
		wp_enqueue_script( 'easy-responsive-tabs', get_template_directory_uri() . '/js/easy-responsive-tabs.js', array(), '1.0', true );
		wp_enqueue_script( 'site_functions', get_template_directory_uri() . '/js/site_functions.js', array(), '1.0', true );

    }

}

add_action( 'wp_enqueue_scripts', 'enqueue_scripts' );