title: Why can't Firefox or Chrome determine a .json file's type?
body: <p>For an <code>&lt;input type="file"&gt;</code> neither Firefox(34.0.5) nor Chrome(39.0.2171.95 (64-bit)) can determine a .json file's type. You can try it with the following code:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
    &lt;title&gt;Test&lt;/title&gt;
  &lt;/head&gt;
  
  &lt;body&gt;
  
    &lt;input type="file" id="file_input" name="files[]" multiple /&gt;
  
  &lt;script type='text/javascript' src='lib/jquery-1.9.1.js'&gt;&lt;/script&gt;
  &lt;script&gt;
  $("#file_input").on('change', function(evt) {
  
    var files = evt.target.files; 
    //files is a FileList of File objects.
    var i;
    var len = files.length;
  
    for (i=0; i &lt; len; ++i) {
      console.log(files[i]);
      console.log("Type: " + files[i].type);
    }
  })
  &lt;/script&gt;
  
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>