Webamator

YouTube iframe embeds often load many unnecessary resources, which slows down your page. YEP: Optimize YouTube Embeds is a lightweight WordPress plugin that replaces YouTube iframes with a clickable preview image. 
The actual video loads only when the user clicks the play button, improving page load times and reducing initial page size.
<h3>External services</h3>
This plugin uses the external YouTube thumbnail service (https://i.ytimg.com) to display preview images of YouTube videos. 
When a page with a YouTube embed is loaded, the plugin requests the thumbnail image directly from YouTube servers. 
No personal data is sent from your site to YouTube, only the video ID (already public in the YouTube URL).
Privacy Policy: https://policies.google.com/privacy 
Terms of Service: https://www.youtube.com/t/terms

YEP: Optimize YouTube Embeds

Short Description: Load YouTube videos faster by replacing iframes with a preview image; the video plays only when clicked play.

Masud Rana

Ruth Kuttler

This WordPress responsive designer fast-loading video player with short code generator makes it easy to add beautiful embedded video to any page or post.
Features include:
<ul>
<li>Responsive designer player with rounded corners and drop shadow.</li>
<li>Embed video by inserting short code on any page or post.</li>
<li>Compatible with all WordPress themes.</li>
<li>Fast performance by loading thumbnail only until play button is clicked.</li>
<li>Loads video files that slow the site only when video is played.</li>
<li>Generates short code with choice of adding ID or URL from YouTube or Vimeo to generate.</li>
</ul>

Fast and Responsive Youtube Vimeo Embed

Free Responsive Fast-Loading Designer Video Embed Player for YouTube and Vimeo

YEP: Optimize YouTube Embeds vs Fast and Responsive Youtube Vimeo Embed