JSFiddle - React, Tailwind, and code Playground

HTML

<form class="changedOnly" method="post">
    <input type="text" name="name" value="alex" />
    <input type="radio" name="age" value="20" checked="checked" />
    <input type="radio" name="age" value="30" />
    <input type="submit" name="Send" />
</form>

JavaScript

$('document').ready(function() {
    $('.changedOnly').each(function() {
        $(this).data('initial', $(this).serialize());
    });
    $('.changedOnly').on('submit',function (event) {             
        var msg = $(this).data('initial') == $(this).serialize() ? 'beze změny' : 'změněno';
        event.preventDefault();
        alert(msg);
    });
});