FormData()

The FormData() constructor creates a new FormData object.

Syntax

var formData = new FormData(form)

Parameters

form Optional

An HTML <form> element — when specified, the FormData object will be populated with the form's current keys/values. It will also encode file input content.

Example

The following line creates an empty FormData object:

var formData = new FormData(); // Currently empty

You could add a key/value pair to this using (domxref("FormData.append")}}:

formData.append('username', 'Chris');

Or you can specify the optional form argument when creating the FormData object, to prepopulate it with values from the specified form:

<form id="myForm" name="myForm">
  <div>
    <label for="username">Enter name:</label>
    <input type="text" id="username" name="username">
  </div>
  <div>
    <label for="useracc">Enter account number:</label>
    <input type="text" id="useracc" name="useracc">
  </div>
  <div>
    <label for="userfile">Enter name:</label>
    <input type="file" id="userfile" name="userfile">
  </div>
<input type="submit" value="Submit!">
</form>

var myForm = document.querySelector('form');
formData = new FormData(myForm);

Specifications

Browser compatibility