Web/API/XMLHTTPRequest/sendAsBinary

The obsolete XMLHttpRequest method sendAsBinary() is a variant of the send() method that sends binary data. The send() method now supports binary data and should now be used instead.

This method makes it possible to read and upload any type of file and to stringify the raw data.

Warning: This method is obsolete and should not be used. You should instead simply use the send() method, which now supports binary data in various forms.

Syntax

XMLHttpRequest.sendAsBinary(binaryString);

Parameters

binaryString: A DOMString which encodes the binary content to be sent. You can create the binary string using the FileReader method readAsBinaryString(). The string is converted to binary for transfer by removing the high-order byte of each character.

Return value

undefined.

Polyfill

Since sendAsBinary() is an experimental feature, here is a polyfill for browsers that don't support the sendAsBinary() method but support typed arrays.

/*\
|*|
|*|  :: XMLHttpRequest.prototype.sendAsBinary() Polyfill ::
|*|
|*|  https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest#sendAsBinary()
|*|
\*/

if (!XMLHttpRequest.prototype.sendAsBinary) {
  XMLHttpRequest.prototype.sendAsBinary = function (sData) {
    var nBytes = sData.length, ui8Data = new Uint8Array(nBytes);
    for (var nIdx = 0; nIdx < nBytes; nIdx++) {
      ui8Data[nIdx] = sData.charCodeAt(nIdx) & 0xff;
    }
    /* send as ArrayBufferView...: */
    this.send(ui8Data);
    /* ...or as ArrayBuffer (legacy)...: this.send(ui8Data.buffer); */
  };
}

Note: It's possible to build this polyfill putting two types of data as argument for send(): an ArrayBuffer (ui8Data.buffer – the commented code) or an ArrayBufferView (ui8Data, which is a typed array of 8-bit unsigned integers – uncommented code). However, on Google Chrome, when you try to send an ArrayBuffer, the following warning message will appear: ArrayBuffer is deprecated in XMLHttpRequest.send(). Use ArrayBufferView instead. Another possible approach to send binary data is the StringView Non native typed arrays superclass in conjunction with the send() method.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`sendAsBinary` Deprecated'Non-standard'	Chrome No support No Notes' No support No Notes' Notes' There is a polyfill available to support `sendAsBinary()`.	Edge No support No Notes' No support No Notes' Notes' There is a polyfill available to support `sendAsBinary()`.	Firefox No support 2 — 31	IE No support No	Opera No support No	Safari No support No	WebView Android No support No Notes' No support No Notes' Notes' There is a polyfill available to support `sendAsBinary()`.	Chrome Android No support No Notes' No support No Notes' Notes' There is a polyfill available to support `sendAsBinary()`.	Firefox Android No support 4 — 31	Opera Android No support No	Safari iOS No support No	Samsung Internet Android No support No Notes' No support No Notes' Notes' There is a polyfill available to support `sendAsBinary()`.

Legend

No support: No support
Non-standard. Expect poor cross-browser support.': Non-standard. Expect poor cross-browser support.
Deprecated. Not for use in new websites.': Deprecated. Not for use in new websites.
See implementation notes.': See implementation notes.

Using XMLHttpRequest

XMLHttpRequest.sendAsBinary() by Mozilla Contributors is licensed under CC-BY-SA 2.5.