Docs4dev
Docs
dom / latest / blob / blob.html

Blob: Blob() constructor

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

js

new Blob(array)
new Blob(array, options)

Parameters

array

An iterable object such as an Array, having ArrayBuffers, TypedArrays, DataViews, Blobs, strings, or a mix of any of such elements, that will be put inside the Blob. Strings should be well-formed Unicode, and lone surrogates are sanitized using the same algorithm as String.prototype.toWellFormed().

options Optional

An object 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 the value native.

Return value

A new Blob object containing the specified data.

Examples

js

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

Specifications

Specification
File API
# constructorBlob

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
Blob 20 12
13Before Firefox 16, the second parameter, when set to null or undefined, leads to an error instead of being handled as an empty dictionary.
10IE10 throws InvalidStateError with a TypedArray argument. Consider using MSBuilder as an alternative.
12 6 4.4 25
14Before Firefox 16, the second parameter, when set to null or undefined, leads to an error instead of being handled as an empty dictionary.
12 6 1.5

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Blob/Blob