FormData vs jQuery#serialize(), What is the difference?

Question

Recently I was submitting a form using AJAX.

In researching the best method I saw some AJAX submissions using jQuery#serialize() and others using FormData. For example.

One submission did this:

data: $('form').serialize()

while the other did:

var formData = new FormData($('form')[0]);
data: formData

So what is the difference between FormData and jQuery#serialize()?

Achernar

Answer 1

The main difference from a usage standpoint is that you can't serialize files, only file names....the value of a file input.

FormData object on the other hand also includes files if applicable.

Also serialize() will work in older browsers that don't support the FormData API for example IE < 10

reference FormData docs

Nitrobenzene

Answer 2

One more important difference is the treatment of empty input-fields in forms.

serialize()

only contains input-fields with a value. Unchecked check-boxes or empty input-fields will be missing in the key/value pairs. Therefore the backend of your application will have to do some book-keeping in order to interpret missing keys as empty values.

FormData

will get you a complete list of all your form fields and their values. Even if they are empty.

Eightieth

Answer 3

When sending data through an AJAX call, two options are commonly used: FormData and serialize(). While both methods have limitations, they serve different purposes:

• FormData:
  • Allows sending selected files along with other field values.
  • Limitation: Excludes textarea content.
• serialize():
  • Can capture all data values, including textarea contents.
  • Limitation: Excludes selected files.

In summary, FormData is ideal for sending files, while serialize() is better suited for sending text data, including textarea values.

Supervision