The Request()
constructor creates a new Request
object.
Syntax
var myRequest = new Request(input[, init]);
Parameters
- input
- Defines the resource that you wish to fetch. This can either be:
- A
USVString
containing the direct URL of the resource you want to fetch. - A
Request
object, effectively creating a copy. Note the following behavioural updates to retain security while making the constructor less likely to throw exceptions:- If this object exists on another origin to the constructor call, the
Request.referrer
is stripped out. - If this object has a
Request.mode
ofnavigate
, themode
value is converted tosame-origin
.
- If this object exists on another origin to the constructor call, the
- A
- init Optional
- An options object containing any custom settings that you want to apply to the request. The possible options are:
method
: The request method, e.g.,GET
,POST
. The default isGET
.headers
: Any headers you want to add to your request, contained within aHeaders
object or an object literal withByteString
values.body
: Any body that you want to add to your request: this can be aBlob
,BufferSource
,FormData
,URLSearchParams
,USVString
, orReadableStream
object. Note that a request using theGET
orHEAD
method cannot have a body.mode
: The mode you want to use for the request, e.g.,cors
,no-cors
,same-origin
, ornavigate
. The default iscors
.credentials
: The request credentials you want to use for the request:omit
,same-origin
, orinclude
. The default issame-origin
.cache
: The cache mode you want to use for the request.redirect
: The redirect mode to use:follow
,error
, ormanual
. The default isfollow
.referrer
: AUSVString
specifyingno-referrer
,client
, or a URL. The default isabout:client
.integrity
: Contains the subresource integrity value of the request (e.g.,sha256-BpfBw7ivV8q2jLiT13fxDYAe2tJllusRSZ273h2nFSE=
).
Errors
Type | Description |
---|---|
TypeError |
Since Firefox 43, Request() will throw a TypeError if the URL has credentials, such as http://user:password@example.com. |
Example
In our Fetch Request example (see Fetch Request live) we create a new Request
object using the constructor, then fetch it using a GlobalFetch.fetch
call. Since we are fetching an image, we run Body.blob
on the response to give it the proper MIME type so it will be handled properly, then create an Object URL of it and display it in an <img>
element.
var myImage = document.querySelector('img'); var myRequest = new Request('flowers.jpg'); fetch(myRequest).then(function(response) { return response.blob(); }).then(function(response) { var objectURL = URL.createObjectURL(response); myImage.src = objectURL; });
In our Fetch Request with init example (see Fetch Request init live) we do the same thing except that we pass in an init object when we invoke fetch()
:
var myImage = document.querySelector('img'); var myHeaders = new Headers(); myHeaders.append('Content-Type', 'image/jpeg'); var myInit = { method: 'GET', headers: myHeaders, mode: 'cors', cache: 'default' }; var myRequest = new Request('flowers.jpg',myInit); fetch(myRequest).then(function(response) { ... });
Note that you could also pass the init object into the fetch
call to get the same effect, e.g.:
fetch(myRequest,myInit).then(function(response) { ... });
You can also use an object literal as headers
in init
.
var myInit = { method: 'GET', headers: { 'Content-Type': 'image/jpeg' }, mode: 'cors', cache: 'default' }; var myRequest = new Request('flowers.jpg', myInit);
You may also pass a Request
object to the Request()
constructor to create a copy of the Request (This is similar to calling the clone()
method.)
var copy = new Request(myRequest);
Note: This last usage is probably only useful in ServiceWorkers.
Specifications
Specification | Status | Comment |
---|---|---|
Fetch The definition of 'Request()' in that specification. |
Living Standard |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Request() constructor | Chrome
Full support
41
| Edge Full support 15 | Firefox
Full support
39
| IE No support No | Opera
Full support
29
| Safari Full support 10.1 | WebView Android
Full support
42
| Chrome Android
Full support
41
| Firefox Android
Full support
39
| Opera Android
Full support
29
| Safari iOS Full support 10.3 | Samsung Internet Android
Full support
4.0
|
cross-origin referrer stripped out and navigate mode converted to same-origin when constructor created from existing Request object. | Chrome Full support Yes | Edge Full support 15 | Firefox Full support 54 | IE No support No | Opera Full support Yes | Safari Full support 10.1 | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android No support No | Safari iOS Full support 10.3 | Samsung Internet Android Full support Yes |
navigate mode | Chrome Full support 49 | Edge Full support 15 | Firefox Full support 46 | IE No support No | Opera Full support Yes | Safari Full support 10.1 | WebView Android No support No | Chrome Android Full support 49 | Firefox Android Full support Yes | Opera Android No support No | Safari iOS Full support 10.3 | Samsung Internet Android Full support 5.0 |
Send ReadableStream in request body | Chrome No support No | Edge No support No | Firefox No support No | IE No support No | Opera ? | Safari No support No | WebView Android No support No | Chrome Android No support No | Firefox Android No support No | Opera Android No support No | Safari iOS No support No | Samsung Internet Android No support No |
referrer init option | Chrome ? | Edge Full support 15 | Firefox Full support 47 | IE No support No | Opera Full support Yes | Safari Full support 10.1 | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android No support No | Safari iOS Full support 10.3 | Samsung Internet Android Full support Yes |
Consume response body as a ReadableStream | Chrome Full support 43 | Edge Full support ≤79 | Firefox
Full support
65
| IE No support No | Opera ? | Safari No support No | WebView Android Full support 43 | Chrome Android Full support 43 | Firefox Android
Full support
65
| Opera Android No support No | Safari iOS Full support 10.3 | Samsung Internet Android Full support 4.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- Experimental. Expect behavior to change in the future.
- Experimental. Expect behavior to change in the future.
- See implementation notes.
- See implementation notes.
- User must explicitly enable this feature.
- User must explicitly enable this feature.