JSFiddle - React, Tailwind, and code Playground

HTML

<div style="color:blue">Some <em>rich</em> <span style="font-size:2em">HTML</span></div>
<br />
<div style="border:1px solid red" contenteditable></div>
<br />
<div style="border:1px solid red" contenteditable></div>

CSS

div[contenteditable] {
    height: 50px;
}

JavaScript

var editors = document.querySelectorAll("div[contenteditable]");
for(var i = 0, l = editors.length; i < l; i++) {
    editors[i].addEventListener("paste", function(e) {
        e.preventDefault();
        var text = e.clipboardData.getData("text/plain");
        document.execCommand("insertHTML", false, text);
    });
}