Use XMLHttpRequest (XHR) objects 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.

Despite its name, XMLHttpRequest can be used to retrieve any type of data, not just XML, and it supports protocols other than HTTP (including file and ftp).

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 the readyState 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 a DOMString, depending on the value of XMLHttpRequest.responseType. that contains the response entity body.
XMLHttpRequest.responseText Read only
Returns a DOMString that contains the response to the request as text, or null 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 Not available to workers
Returns a Document containing the response to the request, or null if the request was unsuccessful, has not yet been sent, or cannot be parsed as XML or HTML.
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. Unlike XMLHTTPRequest.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-site Access-Control requests should be made using credentials such as cookies or authorization headers.

Non-standard properties

XMLHttpRequest.channelRead only
Is a nsIChannel. The channel used by the object when performing the request.
XMLHttpRequest.mozAnonRead only
Is a boolean. If true, the request will be sent without cookie and authentication headers.
XMLHttpRequest.mozSystemRead 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 only
Is an ArrayBuffer. The response to the request, as a JavaScript typed array.
XMLHttpRequest.multipartObsolete 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. This method is to be used from JavaScript code; to initialize a request from native code, use openRequest() instead.
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()after open(), but before send().

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 for open().
XMLHttpRequest.sendAsBinary()
A variant of the send() method that sends binary data.

Specifications

Specification Status Comment
XMLHttpRequest Living Standard Live standard, latest version

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic supportChrome Full support 1Edge Full support YesFirefox Full support 1IE Full support 7Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support 12Firefox Android Full support 4Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
onreadystatechangeChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 7
Notes
Full support 7
Notes
Notes Internet Explorer version 5 and 6 supported ajax calls using ActiveXObject()
Opera Full support YesSafari Full support 1.2WebView Android Full support 1Chrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
readyStateChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 7Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
responseChrome Full support YesEdge Full support 12Firefox Full support YesIE ? Opera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
responseTextChrome Full support YesEdge Full support 12Firefox Full support YesIE ?
Notes
?
Notes
Notes Before IE 10, the value of XMLHttpRequest.responseText could be read only once the request was complete.
Opera Full support YesSafari Full support 10WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
responseTypeChrome Full support 31Edge Full support 12Firefox Full support 6IE Full support 10Opera Full support 18Safari Full support 7WebView Android Full support 55Chrome Android Full support 55Edge Mobile Full support YesFirefox Android Full support 50Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support 6.0
responseURLChrome Full support 37Edge Full support 14Firefox Full support 32IE No support NoOpera Full support 24Safari Full support 8WebView Android Full support 37Chrome Android Full support 37Edge Mobile ? Firefox Android Full support 32Opera Android Full support 24Safari iOS ? Samsung Internet Android Full support Yes
responseXMLChrome Full support YesEdge Full support 12Firefox Full support Yes
Notes
Full support Yes
Notes
Notes Prior to Firefox 51, an error parsing the received data added a <parsererror> node to the top of the Document and then returned the Document in whatever state it happens to be in. This was inconsistent with the specification. Starting with Firefox 51, this scenario now correctly returns null as per the spec.
IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support Yes
Notes
Full support Yes
Notes
Notes Prior to Firefox 51, an error parsing the received data added a <parsererror> node to the top of the Document and then returned the Document in whatever state it happens to be in. This was inconsistent with the specification. Starting with Firefox 51, this scenario now correctly returns null as per the spec.
Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes
statusChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 7
Notes
Full support 7
Notes
Notes Internet Explorer version 5 and 6 supported ajax calls using ActiveXObject()
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
statusTextChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 7
Notes
Full support 7
Notes
Notes Internet Explorer version 5 and 6 supported ajax calls using ActiveXObject()
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
timeoutChrome Full support 29Edge Full support 12Firefox Full support 12IE Full support 8Opera Full support 17
Full support 17
No support 12 — 16
Safari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
uploadChrome Full support 1Edge Full support 12Firefox Full support YesIE ? Opera Full support YesSafari Full support 10WebView Android Full support YesChrome Android Full support 18Edge Mobile ? Firefox Android ? Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
withCredentialsChrome Full support YesEdge Full support 12Firefox Full support 3.5
Notes
Full support 3.5
Notes
Notes Starting with Firefox 11, it's no longer supported to use the withCredentials attribute when performing synchronous requests. Attempting to do so throws an NS_ERROR_DOM_INVALID_ACCESS_ERR exception.
IE Full support 10
Notes
Full support 10
Notes
Notes Internet Explorer versions 8 and 9 supported cross-domain requests (CORS) using XDomainRequest
Opera Full support 12Safari Full support 4WebView Android Full support YesChrome Android Full support YesEdge Mobile ? Firefox Android Full support 4
Notes
Full support 4
Notes
Notes Starting with Firefox 11, it's no longer supported to use the withCredentials attribute when performing synchronous requests. Attempting to do so throws an NS_ERROR_DOM_INVALID_ACCESS_ERR exception.
Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
abortChrome Full support 18Edge Full support 12Firefox Full support YesIE Full support 7
Full support 7
Full support 5
Notes
Notes Implemented via ActiveXObject
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
getAllResponseHeadersChrome Full support 1Edge Full support 12Firefox Full support 4
Notes
Full support 4
Notes
Notes Starting from Firefox 49, empty headers are returned as empty strings in case the preference network.http.keep_empty_response_headers_as_empty_string is set to true, defaulting to false. Before Firefox 49 empty headers had been ignored. Since Firefox 50 the preference defaults to true.
IE Full support 7
Full support 7
Full support 5
Notes
Notes Implemented via ActiveXObject
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4
Notes
Full support 4
Notes
Notes Starting from Firefox 49, empty headers are returned as empty strings in case the preference network.http.keep_empty_response_headers_as_empty_string is set to true, defaulting to false. Before Firefox 49 empty headers had been ignored. Since Firefox 50 the preference defaults to true.
Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
getResponseHeaderChrome Full support 1Edge Full support 12Firefox Full support Yes
Notes
Full support Yes
Notes
Notes Starting from Firefox 49, empty headers are returned as empty strings in case the preference network.http.keep_empty_response_headers_as_empty_string is set to true, defaulting to false. Before Firefox 49 empty headers had been ignored. Since Firefox 50 the preference defaults to true.
IE Full support 7
Full support 7
Full support 5
Notes
Notes Implemented via ActiveXObject
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support Yes
Notes
Full support Yes
Notes
Notes Starting from Firefox 49, empty headers are returned as empty strings in case the preference network.http.keep_empty_response_headers_as_empty_string is set to true, defaulting to false. Before Firefox 49 empty headers had been ignored. Since Firefox 50 the preference defaults to true.
Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes
openChrome Full support 1Edge Full support 12Firefox Full support Yes
Notes
Full support Yes
Notes
Notes Starting in Firefox 30, synchronous requests on the main thread have been deprecated due to their negative impact on performance and the user experience. Therefore, the async parameter may not be false except in a Worker.
IE Full support 7
Full support 7
Full support 5
Notes
Notes Implemented via ActiveXObject
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support Yes
Notes
Full support Yes
Notes
Notes Starting in Firefox 30, synchronous requests on the main thread have been deprecated due to their negative impact on performance and the user experience. Therefore, the async parameter may not be false except in a Worker.
Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes
overrideMimeTypeChrome Full support 1Edge Full support 12Firefox Full support YesIE Full support 11
Full support 11
Full support 5
Notes
Notes Implemented via ActiveXObject
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes
sendChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 7
Full support 7
Full support 5
Notes
Notes Implemented via ActiveXObject
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes
sendAsBinary
DeprecatedNon-standard
Chrome No support No
Notes
No support No
Notes
Notes There is a polyfill available to support sendAsBinary().
Edge No support NoFirefox No support 2 — 31IE No support NoOpera No support NoSafari No support NoWebView 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().
Edge Mobile No support NoFirefox Android No support 4 — 31Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support No
setRequestHeaderChrome Full support 1Edge Full support 12Firefox Full support YesIE Full support 7
Full support 7
Full support 5
Notes
Notes Implemented via ActiveXObject
Opera Full support YesSafari Full support 1.2WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes

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

Document Tags and Contributors

Last updated by: sideshowbarker,