JSFiddle - React, Tailwind, and code Playground

HTML

<div id="fadedText">Test test test test test test...</div>
<div id="result"></div>

JavaScript

var fadedText='';
var x = $("#fadedText").text().length;
var i = Math.round(99/x);
var p = 99;

jQuery.map($("#fadedText").text().split(''),function(s)
{
   if(s!= '')
   {
     fadedText+='<span style="opacity: 0.' + (p - i) + ';">' + s + '</span>';
     x--;
       p = p - i;
   }
});
$("#result").html(fadedText);