Reduce the impact of third-party code ,optimize JS delivery, Minify, remove unused js, pre connect, inline, lazy load etc

Add below code your WordPress theme functions.php manually not recommended

or try to user wp plugins scripts to footer (this not moves script in the mobile version of mobile.

speed booster pack move all the script but not allows to minify HTML.

Moving javascript footer why it’s important

Other than WordPress  or small HTML pages you can place javascript after closing the </head> and before  closing the </body> tag.

HTML loads first, so the user can see what they want. js Loads meanwhile.

Loading javascript asynchronously and defer parsing js

How to javascript Asynchronously?

just look at the Adsense ad code  <script>

<script async src=”path to js file”></script>

How to defer load / parse Javascript?

Defer loading means wait until the  HTML content then load javascript. quick possible solutions use async or defer. but it not works we need use on load function.

this is deep process only for developers. 90% of people ignore this.

Another thing is Optimize CSS Delivery

Minify CSS: Reducing the size by removing comments & Space This process applicable for JS and HTML too.

CSS Placement: why we have to place CSS in the header. Without CSS Plain HTML Loads it looks like ugly.

Inline CSS: if there is small CSS then try to inline the CSS instead loading from external file.

The best Plugin to cache all resources and serve quickly w3 total cache.

Check out my other thoughts Increase page speed score in google insights 95+, How to  improve page speed

inline critical js small

it’s better online s just like critical css,

mostly responsive menu in mobile.

remove unused js

unload js files with asset cleanup.

Reduce the impact of third-party code

Third-party code blocked the main thread for 710 ms

<link rel=”dns-prefetch” href=”http://example.com”>

<link rel=”preconnect” href=”https://cdn.example.com”>

async and defer js

default behavior for script downloading and parsing is synchronous,

JavaScript marked async will always execute before JavaScript marked defer

Mediavine switched to lazy-loading ads and saw a 200% improvement in page load speed.

by google

service worker

a service worker to determine how often a piece of content should be fetched from the network,

Optimize HTML to Boost Web Performance

Clean up HTML
Don’t use inline styles / scripts.
minify html
compress
cache at browser no need
optimize page  delivery

/** * Load Enqueued Scripts in the Footer * * 
Automatically move JavaScript code to page footer, speeding up page loading time. */ 
function footer_enqueue_scripts() 
{ remove_action('wp_head', 'wp_print_scripts'); 
remove_action('wp_head', 'wp_print_head_scripts', 9); 
remove_action('wp_head', 'wp_enqueue_scripts', 1); 
add_action('wp_footer', 'wp_print_scripts', 5); 
add_action('wp_footer', 'wp_enqueue_scripts', 5); 
add_action('wp_footer', 'wp_print_head_scripts', 5); } 
add_action('after_setup_theme', 'footer_enqueue_scripts');