JSFiddle - React, Tailwind, and code Playground

HTML

Select a file : <input id="fileInput" type="file"><br><br>
 
Html Codes : <textarea id="displayHtml"></textarea><br><br>

<div id="displayPage">Display the Html Page here</div>

JavaScript

function handleFileSelect(evt) {
  var file = evt.target.files[0]; // File inputs are an array - get the first element
  var reader = new FileReader();

  reader.onload = function(e) {
    // Render the supplied file
    document.getElementById('displayHtml').value = e.target.result
    document.getElementById('displayPage').innerHTML = e.target.result;
  };

  // Read in the HTML file.
  reader.readAsText(file);
};

document.getElementById('fileInput').addEventListener('change', handleFileSelect, false);