The blob() method of the Response interface takes a Response stream and reads it to completion. It returns a promise that resolves with a Blob.

Syntax

blob()

Parameters

None.

Return value

A promise that resolves with a Blob whose data is the body's bytes and the media type is the response's Content-Type header's value.

Exceptions

AbortError DOMException

The request was aborted.

TypeError

Thrown for one of the following reasons:

• The response body is disturbed or locked.
• There was an error decoding the body content (for example, because the Content-Encoding header is incorrect).

Examples

In our fetch request example (run fetch request live), we create a new request using the Request() constructor, then use it to fetch a JPG. When the fetch is successful, we read a Blob out of the response using blob(), put it into an object URL using URL.createObjectURL(), and then set that URL as the source of an <img> element to display the image.

const myImage = document.querySelector("img");

const myRequest = new Request("flowers.jpg");

fetch(myRequest)
  .then((response) => response.blob())
  .then((myBlob) => {
    const objectURL = URL.createObjectURL(myBlob);
    myImage.src = objectURL;
  });

Specifications

Browser compatibility

See also

• ServiceWorker API
• HTTP access control (CORS)
• HTTP