JSFiddle - React, Tailwind, and code Playground

HTML

<div contenteditable="true"></div>
<span></span>

CSS

div {
    height: 100px;
    width: 300px;
    border: 1px solid grey;
    outline: 0;
}

JavaScript

$('div').on('keydown', function(event) {
  $('span').text('Total chars:' + $(this).text().length);
  if($(this).text().length === 100 && event.keyCode != 8) {
  	event.preventDefault();
  }
});