JSFiddle - React, Tailwind, and code Playground

HTML

<div id='output'></div>
<input type='text' id='input' />

JavaScript

function parseUrl(url) {
        var parser = document.createElement('a');
        parser.href = url;
      return(parser.hostname);
}

var output = document.getElementById('output');
var input = document.getElementById('input');

input.onkeyup = function(e) {
    output.innerHTML = parseUrl(input.value);
};