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The XMLHttpRequestEventTarget.onload is the function called when an XMLHttpRequest transaction completes successfully.


XMLHttpRequest.onload = callback;


  • callback is the function to be executed when the request completes successfully. It receives a ProgressEvent object as its first argument. The value of this (i.e. the context) is the same XMLHttpRequest this callback is related to.


var xmlhttp = new XMLHttpRequest(),
  method = 'GET',
  url = 'https://developer.mozilla.org/';

xmlhttp.open(method, url, true);
xmlhttp.onload = function () {
  // Do something with the retrieved data ( found in xmlhttp.response )


Specification Status Comment
XMLHttpRequest Living Standard WHATWG living standard

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
onloadChrome Full support YesEdge Full support YesFirefox Full support YesIE ? Opera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes


Full support  
Full support
Compatibility unknown  
Compatibility unknown