Body.blob()

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

Syntax

response.blob().then(function(myBlob) {
  // do something with myBlob
});

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.

Example

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.

var myImage = document.querySelector('img');

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

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

Specifications

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

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
blob
Experimental
Chrome Full support 42
Full support 42
Full support 41
Disabled
Disabled From version 41: this feature is behind the Experimental Web Platform Features preference. To change preferences in Chrome, visit chrome://flags.
Edge Full support ≤18Firefox Full support 39
Full support 39
Full support 34
Disabled
Disabled From version 34: this feature is behind the dom.fetch.enabled preference. To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 29
Full support 29
Full support 28
Disabled
Disabled From version 28: this feature is behind the Experimental Web Platform Features preference.
Safari Full support 10WebView Android No support NoChrome Android Full support 42Firefox Android No support NoOpera Android Full support 29
Full support 29
Full support 28
Disabled
Disabled From version 28: this feature is behind the Experimental Web Platform Features preference.
Safari iOS Full support 10Samsung Internet Android No support No

Legend

Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
User must explicitly enable this feature.
User must explicitly enable this feature.

See also