molotow

Defer Media is a plugin for speed up your website and defer not needed medias which out of the screen when page loaded. 
Then, when you scroll down the page, it will load images/videos/iframes automatically or pre-load it even if it it not visible yet (can be adjusted with Appearance Offset parameters).
This plugin will apply the following actions: 
– Defer images (standard [img] tag and also [picture] src sets) 
– Defer background images (if style=”background-image” applied for some block) 
– Defer Videos ([video], [source] tags) 
– Defer Youtube embedded videos (iframe) 
– Defer any Iframes ([iframe] tag)
You can see plugin demo on this page: 
<a href="https://joomcar.net/wp-optimize/a-lot-of-media-page/" rel="nofollow ugc">Defer Media demo</a>

Defer Media

This plugin defer images and videos loading on your site for make it faster

julienappert

External Files Optimizer

automatically combine and compress css/js files generate with wp_head and wp_footer

Defer Media vs External Files Optimizer