This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The Request() constructor creates a new Request object.


var myRequest = new Request(input, init);


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.
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.
  • headers: Any headers you want to add to your request, contained within a Headers object or an object literal with ByteString values.
  • body: Any body that you want to add to your request: this can be a Blob, BufferSource, FormData, URLSearchParams, or USVString object. Note that a request using the GET or HEAD method cannot have a body.
  • mode: The mode you want to use for the request, e.g., cors, no-cors, same-origin, or navigate. The default is cors. In Chrome the default is no-cors before Chrome 47 and same-origin starting with Chrome 47.
  • credentials: The request credentials you want to use for the request: omit, same-origin, or include. The default is omit. In Chrome the default is same-origin before Chrome 47 and include starting with Chrome 47.
  • cache: The cache mode you want to use for the request: default, no-store, reload, no-cache, or force-cache.
  • redirect: The redirect mode to use: follow, error, or manual. In Chrome the default is follow before Chrome 47 and manual starting with Chrome 47.
  • referrer: A USVString specifying no-referrerclient, or a URL. The default is client.
  • integrity: Contains the subresource integrity value of the request (e.g., sha256-BpfBw7ivV8q2jLiT13fxDYAe2tJllusRSZ273h2nFSE=).


Type Description
TypeError Since Firefox 43, Request() will throw a TypeError if the URL has credentials, such as


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.


Specification Status Comment
The definition of 'Request()' in that specification.
Living Standard  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 42.0 [1]
39 (39) [2] No support

29 [3]

No support
Streaming response body 43.0 ? ? ? ?
navigate mode 49.0 46 (46) No support ? No support
referrer init option ? 47 (47) ? ? ?
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support No support 42 [1] ? No support No support No support No support 42.0 [1]
Streaming response body No support 43.0  ? ? ? ? ? 43.0 
navigate mode No support No support ? No support No support No support No support 49.0 
referrer init option ? ? ? ? ? ? ? ?
  • [1] Some default values for the init parameter changed in Chrome 47. See the Properties section for details. 
  • [2] Behind a preference in 34.
  • [3] Behind a preference in 28.

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Constructor Experimental Expérimental Fetch Reference request Référence