XMLHttpRequest.responseType

The XMLHttpRequest property responseType is an enumerated string value specifying the type of data contained in the response. It also lets the author change the response type. If an empty string is set as the value of responseType, the default value of "text" is used.

Syntax

var type = XMLHttpRequest.responseType;

XMLHttpRequest.responseType = type;

Value

A string taken from the XMLHttpRequestResponseType enum which specifies what type of data the response contains.

The values supported by responseType are the following:

""

An empty responseType string is treated the same as "text", the default type (therefore, as a DOMString.

arraybuffer

The response is a JavaScript ArrayBuffer containing binary data.

blob

The response is a Blob object containing the binary data.

document

The response is an HTML Document or XML XMLDocument, as appropriate based on the MIME type of the received data. See HTML in XMLHttpRequest to learn more about using XHR to fetch HTML content.

json

The response is a JavaScript object created by parsing the contents of received data as JSON.

text

Similar to "arraybuffer", but the data is received in a stream. When using this response type, the value in response is only available in the handler for the progress event, and only contains the data received since the last progress event, rather than the cumulative data received since the request was sent.

ms-stream

The response is part of a streaming download; this response type is only allowed for download requests, and is only supported by Internet Explorer.

Exceptions

InvalidAccessError

An attempt was made to change the value of responseType on anXMLHttpRequest which is in synchronous mode but not in a Worker. For additional details, see Synchronous XHR restrictions below.

Usage notes

Synchronous XHR restrictions

You cannot change the value of responseType in a synchronous XMLHttpRequest except when the request belongs to a Worker. This restriction is designed in part to help ensure that synchronous operations aren't used for large transactions that block the browser's main thread, thereby bogging down the user experience.

XMLHttpRequests are asynchronous by default; they are only placed in synchronous mode by passing false as the value of the optional async parameter when calling open().

Restrictions in Workers

Attempts to set the value of responseType to "document" are ignored in a Worker.

Specifications

Browser compatibility

See also

• Using XMLHttpRequest
• HTML in XMLHttpRequest
• The response data: response, responseText, and responseXML