Automatically converts your JPEG and PNG uploads into Google’s WebP format. This plugin reduces image file sizes by up to 80% without sacrificing visual quality.

Simple WebP Optimizer

Auto-convert JPG/PNG to WebP. Save up to 80% server space and boost site speed with built-in bulk optimization and real-time savings reports.

alexufo

This plugin improves your website page load speed substantially by replacing embedded YouTube videos, or YouTube links with a clickable preview image. The image is the original thumbnail from YouTube and features the play button, so users can click to play video and at that moment all necessary JavaScript will be loaded. It increases your website page load speed, especially on the sites with multiple YT video embeds
Github repo 
https://github.com/Alexufo/youtube-speedload
Just click install and forget!
<h3>How contact to Author?</h3>
alexufo@mail.ru i am online!

Youtube SpeedLoad

Improve rendering speed pages with YouTube players.

Simple WebP Optimizer vs Youtube SpeedLoad