JSFiddle - React, Tailwind, and code Playground

HTML

<form method='post' action='http://gutfullofbeer.net/cgi/echoparams.cgi'>
    <textarea wrap='soft' name='b' id='b'></textarea><br>
    <input type='submit' value='Go' >
    <input type='hidden' name='browser-reported-length' id='count'>
    <input type='hidden' name='jquery-reported-length' id='jqcount'>
</form>
<div id='x'></div>

JavaScript

$('textarea').bind('keyup cut paste blur', function(e) {
    var len = this.value.length, $len = $(this).val().length;
    $('#x').text(len);
    $('#count').val(len);
    $('#jqcount').val($len);
});