JSFiddle - React, Tailwind, and code Playground
HTML
<input type='file' id='file' />
<div id='log'></div>
JavaScript
document.getElementById("file").onchange = change;
function change(e) {
var files = e.target.files;
for (var i = 0; i < files.length; i++) {
document.getElementById('log').innerHTML += files[i].type + "<br />";
}
}