JSFiddle - React, Tailwind, and code Playground

HTML

<form method='post' action='http://gutfullofbeer.net/cgi/echoparams.cgi'>
    <textarea name='b' id='b'></textarea><br>
    <input type='submit' value='Go' wrap='soft'>
</form>
<div id='x'></div>

JavaScript

$('body').delegate('textarea', 'keyup paste blur', function(e) {
    $('#x').text($('#b').val().length);
});