JSFiddle - React, Tailwind, and code Playground

HTML

<form method="post" enctype="multipart/form-data" id="test">
  <input type="file" name="file" accept="image/*"><br />
  <select name="format">
    <option value="0">Binary String</option>
    <option value="1" selected>DataURL (Base64)</option>
    <option value="2">Text</option>
  </select><br />
  <input type="submit">
</form>

<textarea id="fileData" cols="100" rows="20"></textarea>

JavaScript

var form = $('#test');

    form.on('submit', function(e) {
        e.preventDefault();
        var formData = new FormData(form[0]);
        var reader = new FileReader();
        var format = formData.get('format');
        var file = formData.get('file');
        switch (format) {
        	case "0":
          	reader.readAsBinaryString(file);
            break;
          case "1":
          	reader.readAsDataURL(file);
            break;
          case "2":
          	reader.readAsText(file);
            break;
          default:
          	reader.readAsDataURL(file);
            break;
        }
        reader.onloadend = function(e){
            document.getElementById("fileData").innerHTML = e.target.result;
        }
    });