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.
var type = XMLHttpRequest.responseType; XMLHttpRequest.responseType = type;
A string taken from the
XMLHttpRequestResponseType enum which specifies what type of data the response contains.
responseType to a particular value, the author should make sure that the server is actually sending a response compatible with that format. If the server returns data that is not compatible with the
responseType that was set, the value of
response will be
The values supported by
responseType are the following:
- An attempt was made to change the value of
XMLHttpRequestwhich is in synchronous mode but not in a
Worker. For additional details, see Synchronous XHR restrictions below.
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
Restrictions in Workers
Attempts to set the value of
"document" are ignored in a
|XMLHttpRequest||Living Standard||WHATWG living standard|
12 — 16
|No||No||12 — 58||No||No||No|