Response: formData() method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

See full compatibility

Note: This feature is available in Web Workers.

The formData() method of the Response interface takes a Response stream and reads it to completion. It returns a promise that resolves with a FormData object.

Note: This is mainly relevant to service workers. If a user submits a form and a service worker intercepts the request, you could for example call formData() on it to obtain a key-value map, modify some fields, then send the form onwards to the server (or use it locally).

Syntax

formData()

Parameters

None.

Return value

A Promise that resolves with a FormData object.

Exceptions

AbortError DOMException

The request was aborted.

TypeError

Thrown for one of the following reasons:

The response body is disturbed or locked.
There was an error decoding the body content (for example, because the Content-Encoding header is incorrect).
The MIME type of the body cannot be determined from the Content-Type headers included in the response, or is not application/x-www-form-urlencoded or multipart/form-data.
The body cannot be parsed as a FormData object.

Examples

TBD.

Specifications

Specification
Fetch # ref-for-dom-body-formdata①

Browser compatibility

	desktop					mobile							server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS	Bun	Deno	Node.js
`formData`	Chrome – Partial support Chrome 60 (Release date: 2017-07-25) footnote Partial support footnote If the form data is empty, then Chrome throws `TypeError: Failed to fetch`. See bug 40065051 and bug 40764130.	Edge – Partial support Edge 79 (Release date: 2020-01-15) footnote Partial support footnote If the form data is empty, then Edge throws `TypeError: Failed to fetch`. See bug 40065051 and bug 40764130.	Firefox – Full support Firefox 39 (Release date: 2015-07-02) footnote Full support	Opera – Partial support Opera 47 (Release date: 2017-08-09) footnote Partial support footnote If the form data is empty, then Opera throws `TypeError: Failed to fetch`. See bug 40065051 and bug 40764130.	Safari – Partial support Safari 10.1 – 14 (Release date: 2017-03-27) footnote Partial support footnote The method exists but always rejects with `NotSupportedError`. See bug 215671. Safari – Full support Safari 14.1 (Release date: 2021-04-26) footnote Full support	Chrome Android – Partial support Chrome Android 60 (Release date: 2017-08-01) footnote Partial support footnote If the form data is empty, then Chrome Android throws `TypeError: Failed to fetch`. See bug 40065051 and bug 40764130.	Firefox for Android – Full support Firefox for Android 39 (Release date: 2015-07-02) footnote Full support	Opera Android – Partial support Opera Android 44 (Release date: 2017-12-11) footnote Partial support footnote If the form data is empty, then Opera Android throws `TypeError: Failed to fetch`. See bug 40065051 and bug 40764130.	Safari on iOS – Partial support Safari on iOS 10.3 – 14 (Release date: 2017-03-27) footnote Partial support footnote The method exists but always rejects with `NotSupportedError`. See bug 215671. Safari on iOS – Full support Safari on iOS 14.5 (Release date: 2021-04-26) footnote Full support	Samsung Internet – Partial support Samsung Internet 8 (Release date: 2018-07-18) footnote Partial support footnote If the form data is empty, then Samsung Internet throws `TypeError: Failed to fetch`. See bug 40065051 and bug 40764130.	WebView Android – Partial support WebView Android 60 (Release date: 2017-08-01) footnote Partial support footnote If the form data is empty, then WebView Android throws `TypeError: Failed to fetch`. See bug 40065051 and bug 40764130.	WebView on iOS – Partial support WebView on iOS 10.3 – 14 (Release date: 2017-03-27) footnote Partial support footnote The method exists but always rejects with `NotSupportedError`. See bug 215671. WebView on iOS – Full support WebView on iOS 14.5 (Release date: 2021-04-26) footnote Full support	Bun – Full support Bun 1 (Release date: 2023-09-08) footnote Full support	Deno – Full support Deno 1 (Release date: 2020-05-13) footnote Full support	Node.js – Full support Node.js 18 (Release date: 2022-04-19) footnote Full support

Tip: you can click/tap on a cell for more information.

Full support: Full support
Partial support: Partial support
: Has more compatibility info.

Response: formData() method

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