Convert Image Format In Javascript

<form id="cForm" onsubmit="return convert.read()">
  <label>SELECT FORMAT</label>
  <select id="cFormat">
    <option value="webp">WEBP</option>
    <option value="jpeg">JPG</option>
    <option value="png">PNG</option>
    <option value="gif">GIF</option>
  </select>

  <label>CHOOSE FILE</label>
  <input type="file" id="cFile" accept="image/*" required>

  <input type="submit" value="Go">
</form> …