File: File() constructor

Note: This feature is available in Web Workers.

The File() constructor creates a new File object instance.


new File(fileBits, fileName)
new File(fileBits, fileName, options)



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 File. Note that strings here are encoded as UTF-8, unlike the usual JavaScript UTF-16 strings.


A string representing the file name or the path to the file.

options Optional

An options object containing optional attributes for the file. Available options are as follows:

type Optional

A string representing the MIME type of the content that will be put into the file. Defaults to a value of "".

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.

lastModified Optional

A number representing the number of milliseconds between the Unix time epoch and when the file was last modified. Defaults to a value of


const file = new File(["foo"], "foo.txt", {
  type: "text/plain",


File API
# file-constructor

Browser compatibility

BCD tables only load in the browser

See also