JSFiddle - React, Tailwind, and code Playground
HTML
<div>
<img src="https://www.qries.com/images/banner_logo.png"
width="150" height="70">
</div>
JavaScript
var supportsWebP = true; //set this variable properly
for(i = 0; i < length; i++)
{
var image = allImages[i];
var pngSource = image.getAttribute('data-png-source');
image.src = supportsWebP ? pngSource.replace('.png', '.webp') : pngSource;
}