XMLHttpRequest
(XHR) objects are used to interact with servers. You can retrieve data from a URL without having to do a full page refresh. This enables a Web page to update just part of a page without disrupting what the user is doing. XMLHttpRequest
is used heavily in AJAX programming.
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Despite its name, XMLHttpRequest
can be used to retrieve any type of data, not just XML.
If your communication needs to involve receiving event data or message data from a server, consider using server-sent events through the EventSource
interface. For full-duplex communication, WebSockets may be a better choice.
Constructor
XMLHttpRequest()
- The constructor initializes an XMLHttpRequest. It must be called before any other method calls.
Properties
This interface also inherits properties of XMLHttpRequestEventTarget
and of EventTarget
.
XMLHttpRequest.onreadystatechange
- An
EventHandler
that is called whenever thereadyState
attribute changes. XMLHttpRequest.readyState
Read only- Returns an
unsigned short
, the state of the request. XMLHttpRequest.response
Read only- Returns an
ArrayBuffer
,Blob
,Document
, JavaScript object, or aDOMString
, depending on the value ofXMLHttpRequest.responseType
, that contains the response entity body. XMLHttpRequest.responseText
Read only- Returns a
DOMString
that contains the response to the request as text, ornull
if the request was unsuccessful or has not yet been sent. XMLHttpRequest.responseType
- Is an enumerated value that defines the response type.
XMLHttpRequest.responseURL
Read only- Returns the serialized URL of the response or the empty string if the URL is null.
XMLHttpRequest.responseXML
Read only- Returns a
Document
containing the response to the request, ornull
if the request was unsuccessful, has not yet been sent, or cannot be parsed as XML or HTML. Not available in workers. XMLHttpRequest.status
Read only- Returns an
unsigned short
with the status of the response of the request. XMLHttpRequest.statusText
Read only- Returns a
DOMString
containing the response string returned by the HTTP server. UnlikeXMLHttpRequest.status
, this includes the entire text of the response message ("200 OK
", for example).Note: According to the HTTP/2 specification (8.1.2.4 Response Pseudo-Header Fields), HTTP/2 does not define a way to carry the version or reason phrase that is included in an HTTP/1.1 status line.
XMLHttpRequest.timeout
- Is an
unsigned long
representing the number of milliseconds a request can take before automatically being terminated. XMLHttpRequestEventTarget.ontimeout
- Is an
EventHandler
that is called whenever the request times out. XMLHttpRequest.upload
Read only- Is an
XMLHttpRequestUpload
, representing the upload process. XMLHttpRequest.withCredentials
- Is a
Boolean
that indicates whether or not cross-siteAccess-Control
requests should be made using credentials such as cookies or authorization headers.
Non-standard properties
XMLHttpRequest.channel
Read only- Is a
nsIChannel
. The channel used by the object when performing the request. XMLHttpRequest.mozAnon
Read only- Is a boolean. If true, the request will be sent without cookie and authentication headers.
XMLHttpRequest.mozSystem
Read only- Is a boolean. If true, the same origin policy will not be enforced on the request.
XMLHttpRequest.mozBackgroundRequest
- Is a boolean. It indicates whether or not the object represents a background service request.
XMLHttpRequest.mozResponseArrayBuffer
Obsolete since Gecko 6 Read onlyArrayBuffer
. The response to the request, as a JavaScript typed array.XMLHttpRequest.multipart
Obsolete since Gecko 22- This Gecko-only feature, a boolean, was removed in Firefox/Gecko 22. Please use Server-Sent Events, Web Sockets, or
responseText
from progress events instead.
Event handlers
onreadystatechange
as a property of the XMLHttpRequest
instance is supported in all browsers.
Since then, a number of additional event handlers have been implemented in various browsers (onload
, onerror
, onprogress
, etc.). See Using XMLHttpRequest.
More recent browsers, including Firefox, also support listening to the XMLHttpRequest
events via standard addEventListener()
APIs in addition to setting on*
properties to a handler function.
Methods
XMLHttpRequest.abort()
- Aborts the request if it has already been sent.
XMLHttpRequest.getAllResponseHeaders()
- Returns all the response headers, separated by CRLF, as a string, or
null
if no response has been received. XMLHttpRequest.getResponseHeader()
- Returns the string containing the text of the specified header, or
null
if either the response has not yet been received or the header doesn't exist in the response. XMLHttpRequest.open()
- Initializes a request.
XMLHttpRequest.overrideMimeType()
- Overrides the MIME type returned by the server.
XMLHttpRequest.send()
- Sends the request. If the request is asynchronous (which is the default), this method returns as soon as the request is sent.
XMLHttpRequest.setRequestHeader()
- Sets the value of an HTTP request header. You must call
setRequestHeader()
afteropen()
, but beforesend()
.
Non-standard methods
XMLHttpRequest.init()
- Initializes the object for use from C++ code.
Warning: This method must not be called from JavaScript.
XMLHttpRequest.openRequest()
- Initializes a request. This method is to be used from native code; to initialize a request from JavaScript code, use
open()
instead. See the documentation foropen()
. XMLHttpRequest.sendAsBinary()
- A variant of the
send()
method that sends binary data.
Events
abort
- Fired when a request has been aborted, for example because the program called
XMLHttpRequest.abort()
.
Also available via theonabort
property. error
- Fired when the request encountered an error.
Also available via theonerror
property. load
- Fired when an
XMLHttpRequest
transaction completes successfully.
Also available via theonload
property. loadend
- Fired when a request has completed, whether successfully (after
load
) or unsuccessfully (afterabort
orerror
).
Also available via theonloadend
property. loadstart
- Fired when a request has started to load data.
Also available via theonloadstart
property. progress
- Fired periodically when a request receives more data.
Also available via theonprogress
property. timeout
- Fired when progress is terminated due to preset time expiring.
Also available via theontimeout
property.
Specifications
Specification | Status | Comment |
---|---|---|
XMLHttpRequest | Living Standard | Live standard, latest version |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
XMLHttpRequest | Chrome Full support 1 | Edge
Full support
12
| Firefox Full support 1 | IE
Full support
7
| Opera Full support 8 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
abort | Chrome Full support 18 | Edge Full support 12 | Firefox Full support Yes | IE Full support 5 | Opera Full support Yes | Safari Full support 1.2 | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
abort event | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support Yes | IE Full support 10 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
error event | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support Yes | IE Full support 10 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
getAllResponseHeaders | Chrome Full support 1 | Edge Full support 12 | Firefox
Full support
4
| IE Full support 5 | Opera Full support Yes | Safari Full support 1.2 | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android
Full support
4
| Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
getResponseHeader | Chrome Full support 1 | Edge Full support 12 | Firefox
Full support
1
| IE Full support 5 | Opera Full support 8 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android
Full support
4
| Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
load event | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support Yes | IE Full support 9 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
loadend event | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support Yes | IE Full support 10 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
loadstart event | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support Yes | IE Full support 10 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
onreadystatechange | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE Full support 5 | Opera Full support 9 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
open | Chrome Full support 1 | Edge Full support 12 | Firefox
Full support
1
| IE Full support 5 | Opera Full support 8 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android
Full support
4
| Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
overrideMimeType | Chrome Full support 1 | Edge Full support 12 | Firefox Full support Yes | IE
Full support
11
| Opera Full support Yes | Safari Full support 1.2 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 |
progress event | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support Yes | IE Full support 10 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
readyState | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE Full support 7 | Opera Full support 8 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
response | Chrome Full support 9 | Edge Full support 12 | Firefox Full support 6 | IE Full support 10 | Opera Full support 11.6 | Safari Full support 5.1 | WebView Android Full support ≤37 | Chrome Android Full support 18 | Firefox Android Full support 6 | Opera Android Full support 12 | Safari iOS Full support 6 | Samsung Internet Android Full support 1.0 |
responseText | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE
Full support
5
| Opera Full support 8 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
responseType | Chrome Full support 31 | Edge Full support 12 | Firefox Full support 6 | IE Full support 10 | Opera Full support 18 | Safari Full support 7 | WebView Android Full support 55 | Chrome Android Full support 55 | Firefox Android Full support 50 | Opera Android Full support 42 | Safari iOS Full support 7 | Samsung Internet Android Full support 6.0 |
responseURL | Chrome Full support 37 | Edge Full support 14 | Firefox Full support 32 | IE No support No | Opera Full support 24 | Safari Full support 8 | WebView Android Full support 37 | Chrome Android Full support 37 | Firefox Android Full support 32 | Opera Android Full support 24 | Safari iOS Full support Yes | Samsung Internet Android Full support 3.0 |
responseXML | Chrome Full support Yes | Edge Full support 12 | Firefox
Full support
Yes
| IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android
Full support
Yes
| Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
send | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE Full support 5 | Opera Full support 8 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
sendAsBinary | Chrome
No support
No
| Edge
No support
No
| Firefox No support 2 — 31 | IE No support No | Opera No support No | Safari No support No | WebView Android
No support
No
| Chrome Android
No support
No
| Firefox Android No support 4 — 31 | Opera Android No support No | Safari iOS No support No | Samsung Internet Android
No support
No
|
setRequestHeader | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE Full support 5 | Opera Full support 8 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
status | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE
Full support
7
| Opera Full support 8 | Safari Full support 1.2 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 |
statusText | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE
Full support
7
| Opera Full support Yes | Safari Full support 1.2 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 |
timeout | Chrome Full support 29 | Edge Full support 12 | Firefox Full support 12 | IE Full support 8 | Opera
Full support
17
| Safari Full support 6.1 | WebView Android Full support ≤37 | Chrome Android Full support 29 | Firefox Android Full support 14 | Opera Android
Full support
18
| Safari iOS Full support 7 | Samsung Internet Android Full support 2.0 |
timeout event | Chrome Full support Yes | Edge Full support ≤18 | Firefox Full support Yes | IE Full support 10 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
upload | Chrome Full support 1 | Edge Full support 12 | Firefox Full support Yes | IE Full support 10 | Opera Full support Yes | Safari Full support 10 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 |
withCredentials | Chrome Full support 3 | Edge Full support 12 | Firefox
Full support
3.5
| IE
Full support
10
| Opera Full support 12 | Safari Full support 4 | WebView Android Full support ≤37 | Chrome Android Full support 18 | Firefox Android
Full support
4
| Opera Android Full support 12 | Safari iOS Full support 3.2 | Samsung Internet Android Full support 1.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- 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.
See also
XMLSerializer
: Serializing a DOM tree into XML- MDN tutorials covering
XMLHttpRequest
: - HTML5 Rocks — New Tricks in XMLHttpRequest2
- Feature-Policy directive
sync-xhr