The Blob() constructor returns a new Blob object. The content of the blob consists of the concatenation of the values given in the parameter array.

Syntax

var newBlob = new Blob(array, options);

Parameters

array
An Array of ArrayBuffer, ArrayBufferView, Blob, USVString objects, or a mix of any of such objects, that will be put inside the Blob. USVString objects are encoded as UTF-8.
options Optional

An optional object of type BlobPropertyBag which may specify any of the following properties:

type Optional
The MIME type of the data that will be stored into the blob. The default value is the empty string, ("").
endings Optional
How to interpret newline characters (\n) within the contents, if the data is text. The default value, transparent, copies newline characters into the blob without changing them. To convert newlines to the host system's native convention, specify endings.

Return value

A new Blob object containing the specified data.

Example

var aFileParts = ['<a id="a"><b id="b">hey!</b></a>']; // an array consisting of a single DOMString
var oMyBlob = new Blob(aFileParts, {type : 'text/html'}); // the blob

Specification

Specification Status Comment
File API
The definition of 'Blob()' in that specification.
Working Draft Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Blob() constructor
Experimental
Chrome Full support 20Edge ? Firefox Full support 13
Notes
Full support 13
Notes
Notes Before Firefox 16, the second parameter, when set to null or undefined, leads to an error instead of being handled as an empty dictionary.
IE Full support 10Opera Full support 12Safari Full support 8WebView Android Full support 37Chrome Android Full support 25Firefox Android Full support 14
Notes
Full support 14
Notes
Notes Before Firefox 16, the second parameter, when set to null or undefined, leads to an error instead of being handled as an empty dictionary.
Opera Android ? Safari iOS ? Samsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
See implementation notes.
See implementation notes.

See also

  • The deprecated BlobBuilder interface which this constructor replaces.

Document Tags and Contributors

Last updated by: Sheppy,