Using WebP format

webp.html

<!-- 
The browser uses the first listed source that's in 
a format it supports. If the browser does not support 
any of the formats listed in the <source> tags, it 
falls back to loading the image specified by the <img> tag.
-->
<picture>
  <source type="image/webp" srcset="green-environment.webp">
  <source type="image/jpeg" srcset="green-environment.jpg">
  <img src="green-environment.jpg" alt="">
</picture>