Request: formData() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.
Note: This feature is available inWeb Workers.
TheformData() method of theRequest interfacereads the request body and returns it as a promise that resolves with aFormData object.
Syntax
js
formData()Parameters
None.
Return value
Exceptions
TypeErrorThrown for one of the following reasons:
- The request body isdisturbed or locked.
- There was an error decoding the body content (for example, because the
Content-Encodingheader is incorrect). - TheMIME type of the body cannot be determined from the
Content-Typeheaders included in the request, or is notapplication/x-www-form-urlencodedormultipart/form-data. - The body cannot be parsed as a
FormDataobject.
Examples
js
const formData = new FormData();const fileField = document.querySelector('input[type="file"]');formData.append("username", "abc123");formData.append("avatar", fileField.files[0]);const request = new Request("/myEndpoint", { method: "POST", body: formData,});request.formData().then((data) => { // do something with the formdata sent in the request});Specifications
| Specification |
|---|
| Fetch # ref-for-dom-body-formdata① |