Response
Baseline
Widely available
*
This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2017.
* Some parts of this feature may have varying levels of support.
Note: This feature is available in Web Workers.
The Response interface of the Fetch API represents the response to a request.
You can create a new Response object using the Response() constructor, but you are more likely to encounter a Response object being returned as the result of another API operation—for example, a service worker FetchEvent.respondWith, or a simple fetch().
Constructor
Response()-
Creates a new
Responseobject.
Instance properties
Response.bodyRead only-
A
ReadableStreamof the body contents. Response.bodyUsedRead only-
Stores a boolean value that declares whether the body has been used in a response yet.
Response.headersRead only-
The
Headersobject associated with the response. Response.okRead only-
A boolean indicating whether the response was successful (status in the range
200–299) or not. Response.redirectedRead only-
Indicates whether or not the response is the result of a redirect (that is, its URL list has more than one entry).
Response.statusRead only-
The status code of the response. (This will be
200for a success). Response.statusTextRead only-
The status message corresponding to the status code. (e.g.,
OKfor200). Response.typeRead only-
The type of the response (e.g.,
basic,cors). Response.urlRead only-
The URL of the response.
Static methods
Response.error()-
Returns a new
Responseobject associated with a network error. Response.redirect()-
Returns a new response with a different URL.
Response.json()-
Returns a new
Responseobject for returning the provided JSON encoded data.
Instance methods
Response.arrayBuffer()-
Returns a promise that resolves with an
ArrayBufferrepresentation of the response body. Response.blob()-
Returns a promise that resolves with a
Blobrepresentation of the response body. Response.bytes()-
Returns a promise that resolves with a
Uint8Arrayrepresentation of the response body. Response.clone()-
Creates a clone of a
Responseobject. Response.formData()-
Returns a promise that resolves with a
FormDatarepresentation of the response body. Response.json()-
Returns a promise that resolves with the result of parsing the response body text as
JSON. Response.text()-
Returns a promise that resolves with a text representation of the response body.
Examples
>Fetching an image
In our basic fetch example (run example live) we use a simple fetch() call to grab an image and display it in an <img> element.
The fetch() call returns a promise, which resolves to the Response object associated with the resource fetch operation.
You'll notice that since we are requesting an image, we need to run Response.blob to give the response its correct MIME type.
const image = document.querySelector(".my-image");
fetch("flowers.jpg")
.then((response) => response.blob())
.then((blob) => {
const objectURL = URL.createObjectURL(blob);
image.src = objectURL;
});
You can also use the Response() constructor to create your own custom Response object:
const response = new Response();
A PHP Call
Here we call a PHP program file that generates a JSON string, displaying the result as a JSON value.
// Function to fetch JSON using PHP
const getJSON = async () => {
// Generate the Response object
const response = await fetch("getJSON.php");
if (response.ok) {
// Get JSON value from the response body
return response.json();
}
throw new Error("*** PHP file not found");
};
// Call the function and output value or error message to console
getJSON()
.then((result) => console.log(result))
.catch((error) => console.error(error));
Specifications
| Specification |
|---|
| Fetch> # response-class> |
Browser compatibility
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