The Request
interface of the Fetch API represents a resource request.
You can create a new Request
object using the Request.Request()
constructor, but you are more likely to encounter a Request
object being returned as the result of another API operation, such as a service worker FetchEvent.request
.
Request.Request()
Request
object.Request.cache
Read only
default
, reload
, no-cache
).Request.context
Read only
audio
, image
, iframe
, etc.)Request.credentials
Read only
"omit"
, "same-origin"
, "include"
). The default is "same-origin"
.Request.destination
Read only
RequestDestination
enum describing the request's destination. This is a string indicating the type of content being requested.Request.headers
Read only
Headers
object of the request.Request.integrity
Read only
sha256-BpfBw7ivV8q2jLiT13fxDYAe2tJllusRSZ273h2nFSE=
).Request.method
Read only
GET
, POST
, etc.)Request.mode
Read only
cors
, no-cors
, same-origin
, navigate
.)Request.redirect
Read only
follow
, error
, or manual
.Request.referrer
Read only
client
).Request.referrerPolicy
Read only
no-referrer
).Request.url
Read only
Request
implements Body
, so it also inherits the following properties:
body
Read only
ReadableStream
of the body contents.bodyUsed
Read only
Boolean
that declares whether the body has been used in a response yet.Request.clone()
Request
object.Request
implements Body
, so it also has the following methods available to it:
Body.arrayBuffer()
ArrayBuffer
representation of the request body.Body.blob()
Blob
representation of the request body.Body.formData()
FormData
representation of the request body.Body.json()
JSON
representation of the request body.Body.text()
USVString
(text) representation of the request body.Note: The Body
functions can be run only once; subsequent calls will resolve with empty strings/ArrayBuffers.
In the following snippet, we create a new request using the Request()
constructor (for an image file in the same directory as the script), then return some property values of the request:
const myRequest = new Request('http://localhost/flowers.jpg'); const myURL = myRequest.url; // http://localhost/flowers.jpg const myMethod = myRequest.method; // GET const myCred = myRequest.credentials; // same-origin
You could then fetch this request by passing the Request
object in as a parameter to a WindowOrWorkerGlobalScope.fetch()
call, for example:
fetch(myRequest) .then(response => response.blob()) .then(blob => { myImage.src = URL.createObjectURL(blob); });
In the following snippet, we create a new request using the Request()
constructor with some initial data and body content for an api request which need a body payload:
const myRequest = new Request('http://localhost/api', {method: 'POST', body: '{"foo":"bar"}'}); const myURL = myRequest.url; // http://localhost/api const myMethod = myRequest.method; // POST const myCred = myRequest.credentials; // same-origin const bodyUsed = myRequest.bodyUsed; // true
Note: The body type can only be a Blob
, BufferSource
, FormData
, URLSearchParams
, USVString
or ReadableStream
type, so for adding a JSON object to the payload you need to stringify that object.
You could then fetch this api request by passing the Request
object in as a parameter to a WindowOrWorkerGlobalScope.fetch()
call, for example and get the response:
fetch(myRequest) .then(response => { if (response.status === 200) { return response.json(); } else { throw new Error('Something went wrong on api server!'); } }) .then(response => { console.debug(response); // ... }).catch(error => { console.error(error); });
Specification | Status | Comment |
---|---|---|
Fetch The definition of 'Request' in that specification. | Living Standard | Initial definition |
Desktop | ||||||
---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
Basic support | 42 | Yes | 39 | No | 28 | No |
Request() constructor
|
42
|
15 | 39
|
No | 29
|
10.1 |
cache
|
No | Yes | 48 | No | No | 11 |
clone
|
42
|
Yes | 39
|
No | 29
|
No |
context
|
42 — 46 | ? | 39 — 42
|
No | 28 — 29 | No |
credentials
|
42
|
Yes | 39
|
No | 29
|
No |
destination
|
65 | 14 | 61 | No | 52 | No |
headers
|
42
|
Yes | 39
|
No | 29
|
No |
integrity
|
46 | Yes | Yes | No | Yes | No |
keepalive
|
66 | 15 | ? | ? | 43 | ? |
method
|
42
|
Yes | 39
|
No | 29
|
No |
mode
|
42 | Yes | 39 | No | 29 | No |
redirect
|
46 | Yes | Yes | No | Yes | No |
referrer
|
42
|
Yes | 47 | No | 29
|
No |
referrerPolicy |
52 | No | 52 | No | 39 | 11.1 |
signal |
? | 16 | ? | ? | ? | ? |
url
|
42
|
Yes | 39
|
No | 29
|
No |
Mobile | |||||||
---|---|---|---|---|---|---|---|
Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
Basic support | 42 | 42 | Yes | Yes | 28 | No | 4.0 |
Request() constructor
|
42
|
42
|
Yes | Yes | No | 10.3 | 4.0
|
cache
|
No | No | Yes | No | No | No | No |
clone
|
No | No | Yes | No | No | No | No |
context
|
42 — 46 | 42 — 46 | ? | No | No | No | 4.0 |
credentials
|
No | 42 — 46 | Yes | No | No | No | 4.0 |
destination
|
? | 65 | ? | 61 | 52 | No | ? |
headers
|
No | 42 — 46 | Yes | No | No | No | 4.0 |
integrity
|
No | 46 | Yes | No | Yes | No | 5.0 |
keepalive
|
No | 66 | ? | ? | 43 | ? | No |
method
|
No | 42 — 46 | Yes | No | No | No | 4.0 |
mode
|
49 | 49 | Yes | No | No | No | 5.0 |
redirect
|
No | 46 | Yes | Yes | Yes | No | 5.0 |
referrer
|
No | No | Yes | No | No | No | No |
referrerPolicy |
52 | 52 | No | 52 | 39 | No | 7.2 |
signal |
? | ? | ? | ? | ? | ? | ? |
url
|
42
|
42
|
Yes | No | 29
|
No | 4.0 |
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Request