clebermind

When we embed youtube videos on a page it calls for some URLs and it’s hard to get off to improve the score on page speed. 
This plugin put an image thumb of the video with a play button instead of the youtube video. Simple and fast, just put a shortcode and it is working! 
A CSS+JS solution using a Youtube automatic thumb or your hosted preferred thumb! 
This plugin is based on https://wordpress.org/plugins/optimise-youtube-video-embed/

Optimize YouTube Video Embed

Embed Youtube Video using the shortcode [youtube_iframe]. It shows a youtube thumb of the video(or custom thumb set) and loads the youtube video just  …

Frank Goossens

Optimizing Matters

EricJohnsonGuru

Eliminate Render-blocking Javascript in above-the-fold content with Async Javascript.
Render-blocking Javascript prevents above-the-fold content on your page from being rendered until the javascript has finished loading. This can impact on your page speed and ultimately your ranking within search engines. It can also impact your user’s experience.
Async JavaScript gives you full control of which scripts to add an ‘async’ or ‘defer’ attribute to or to exclude to help increase the performance of your WordPress website.

Async JavaScript

Plugin works as expected, settings are nice and minimal (using core styles) and there aren't any banners, notices or other marketing bloating things up.

Works great!

Async Javascript lets you add 'async' or 'defer' attribute to scripts to exclude to help increase the performance of your WordPres …

Optimize YouTube Video Embed vs Async JavaScript