JSFiddle - React, Tailwind, and code Playground

HTML

<div id="text">Hello World!</div>

JavaScript

var all ="ABCDEFGHIJKLMNOPQRSTUVWXYZa{}[];:></?bcdefghijklmnopqrstuvwxyz0123+_)(*&^%$#@!~`456789";
var old_text;
var flag = 0;

function randChar() {
    "use strict";
    return all.charAt(Math.floor(Math.random()*all.length));   
}
function main() {
    "use strict";
    old_text = document.getElementById("text").textContent;
    var counter = Math.floor(Math.random()*document.getElementById("text").textContent.length);
    var $_inter = setInterval(function() {

        var text = document.getElementById("text");

        text.innerHTML = text.innerHTML.substring(0, 5) + randChar() + text.innerHTML.substring(5);
        setTimeout(function(){
            text.innerHTML = old_text;
        },200);
        flag = flag+1;
    }, 350);
}
window.onload = main;