Response.clone()

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use 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 spec changes.

The clone() method of the Response interface creates a clone of a response object, identical in every way, but stored in a different variable.

clone() throws a TypeError if the response Body has already been used. In fact, the main reason clone() exists is to allow multiple uses of Body objects (when they are one-use only.)

Syntax

JavaScript
var <var>response2</var> = <var>response1</var>.clone();

Parameters

None.

Value

A Response object.

Example

In our Fetch Response clone example (see Fetch Response clone live) we create a new Request object using the Request() constructor, passing it a JPG path. We then fetch this request using fetch(). When the fetch resolves successfully, we clone it, extract a blob from both responses using two Body.blob calls, create object URLs out of the blobs using URL.createObjectURL, and display them in two separate <img> elements.

JavaScript
var image1 = document.querySelector('.img1');
var image2 = document.querySelector('.img2');

var myRequest = new Request('flowers.jpg');

fetch(myRequest).then(function(response) {
  var response2 = response.clone();

  response.blob().then(function(myBlob) {
    var objectURL = URL.createObjectURL(myBlob);
    image1.src = objectURL;
  });

  response2.blob().then(function(myBlob) {
    var objectURL = URL.createObjectURL(myBlob);
    image2.src = objectURL;
  });
});

Specifications

Specification Status Comment
Fetch
The definition of 'clone()' in that specification.
Living Standard Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 42
41[1]
39 (39)
34[1]
Not supported

29
28[1]

Not supported
Feature Android Firefox Mobile (Gecko) Firefox OS (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support Not supported Not supported Not supported Not supported Not supported Not supported Not supported

[1] This feature is implemented behind a preference.

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/response/clone

API clone Experimental Fetch Method Reference Response