JSFiddle - React, Tailwind, and code Playground
HTML
<body>
<form>
<textarea name="text"></textarea>
<p>0</p>
<button type="submit">SEND</button>
</form>
</body>
JavaScript
$("textarea").keyup(function() {
var len = $("textarea").val().length;
$("p").text(len);
});
$("form").on("submit", function(e) {
e.preventDefault();
var ser = $("form").serialize();
$("p").text(ser);
});