Javascript code that shuffles the text of an HTML element

text_shuffle.js

!function () {
    const shuffleVelocityMs = 50;

    const shuffleElement = (element) => {
        const elemText = element.getAttribute("data-text");
        const elemementChars = Array.from(elemText);

        const shuffleChars = (chars) => {
            for (let idx = chars.length; --idx; ) {
                const randomIdx = parseInt(Math.random() * idx);
                const cachedChar = chars[idx];

                chars[idx] = chars[randomIdx];
                chars[randomIdx] = cachedChar;
            }

            return chars;
        };

        const shuffleText = (chars_no, char_idx) => {
            if (char_idx == chars_no) {
                element.textContent = elemText;
                return;
            }

            setTimeout(() => {
                const randomChars = shuffleChars(elemementChars.slice(char_idx));
                element.textContent = elemementChars
                    .slice(0, char_idx)
                    .concat(randomChars)
                    .join("");

                shuffleText(chars_no, ++char_idx);
            }, shuffleVelocityMs);
        };

        shuffleText(elemementChars.length, 0);
    };

    setTimeout(() => {
        const element = document.querySelector(".shuffle");
        element.setAttribute("data-text", element.textContent);
        shuffleElement(element);
    }, 100);
}();

text_shuffle.min.js

!function(){const t=t=>{const e=t.getAttribute("data-text"),n=Array.from(e),o=(c,r)=>{r!=c?setTimeout((()=>{const e=(t=>{for(let e=t.length;--e;){const n=parseInt(Math.random()*e),o=t[e];t[e]=t[n],t[n]=o}return t})(n.slice(r));t.textContent=n.slice(0,r).concat(e).join(""),o(c,++r)}),50):t.textContent=e};o(n.length,0)};setTimeout((()=>{const e=document.querySelector(".shuffle");e.setAttribute("data-text",e.textContent),t(e)}),100)}();

Example at giuseppe.eletto.me.