Response: blob() method
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.
Note: This feature is available in Web Workers.
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.
Note:
If the Response has a
Response.type of "opaque", the resulting Blob
will have a Blob.size of 0 and a Blob.type of
empty string "", which renders it useless for methods like
URL.createObjectURL().
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
AbortErrorDOMException-
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-Encodingheader 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
| Specification |
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| Fetch # ref-for-dom-body-blob① |
Browser compatibility
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Legend
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- Full support
- Full support