JSFiddle - React, Tailwind, and code Playground

HTML

<div id="holder" contentEditable="true">
    Stackoverflow is the <b>coolest</b> Q&amp;A website in the world.
</div>
<br>
<div>nodeName: <span id="nodename"></span></div>

JavaScript

if (document.addEventListener) {
    document.getElementById('holder').addEventListener('mouseover', function (e) {
        document.getElementById('nodename')
                .innerHTML = e.target.nodeName;
    }, false);
} else {
    document.getElementById('holder').attachEvent('onmouseover', function (e) {
        document.getElementById('nodename')
                .innerHTML = e.srcElement.nodeName;
    });
}