JSFiddle - React, Tailwind, and code Playground

HTML

<input type="file" onchange="readFile()">
<img />

JavaScript

var input = document.querySelector('input');
var readFiles = function(){
  var reader = new FileReader();
  reader.readAsDataURL(files[0]);
  console.log(reader.result);

  var img = document.querySelector('img');
  img.src = reader.result;
}