Jill Royer

Every time you upload an image, Simple WebP generates a .webp version. It then alter the HTML to replace img tags with picture tags, which let the browser pick the best format.
WebP images are often smaller than original .jpeg or .png one, so can save bandwidth and load time. Most browsers support WebP nowadays. You can use <a href="https://developers.google.com/speed/pagespeed/insights/" rel="nofollow ugc">Google Pagespeed</a> tool to see the gain you would get from WebP.
You will get much faster load time, and better ranking in Google Search.
Simple WebP is very much inspired by the more complete (and complex to install) <a href="https://fr.wordpress.org/plugins/webp-express/" rel="nofollow ugc">WebP Express</a> plugin. It also use the same libraries :
<ul>
<li><a href="https://github.com/rosell-dk/webp-convert" rel="nofollow ugc">WebPConvert</a>: For converting images to webp</li>
<li><a href="https://github.com/rosell-dk/dom-util-for-webp" rel="nofollow ugc">DOM Util for WebP</a>: For the Alter HTML functionality</li>
</ul>

Simple WebP

For every image uploaded, Simple WebP creates a WebP version which is served to compatible browsers.

alexalouit

This module provide a reliable webp solution, without configuration. 
Supported file formats are JPEG and PNG up to 8 megabytes.
Module look for compatible media images, sends them to an API which is convert them. 
They are saved next to the original file. 
When a visitor is on your site, “HTML Transformation” function take care to provide the WebP version. 
This function can be disabled because some web server takes care of presenting the file themselves.

Simple WebP vs WP WebPNative