JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="ta" oninput="writeIt();">Type here</textarea>
    <iframe id="frm"></iframe>

CSS

textarea,
        iframe {
            display: block;
            width: 100%;
            height: 100px;
        }

JavaScript

function writeIt() {
    var ta = document.getElementById('ta');
    var frm = document.getElementById('frm');
    try {
        var frmDoc = frm.contentDocument;
        frmDoc.open();
        frmDoc.write(ta.value);
        frmDoc.close();
    } 
    catch(err) {
        frm.src = "about:blank";
        setTimeout(writeIt,0);
    }
}