Blob: Blob() constructor

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Note: This feature is available in Web Workers.

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

Syntax

js
new Blob(blobParts)
new Blob(blobParts, options)

Parameters

blobParts Optional

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

Specifications

Specification
File API
# constructorBlob

Browser compatibility