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The initiatorType read-only property is a string that represents the type of resource that initiated the performance event.

The value of this string is as follows:

  • If the initiator is a Element, the property returns the element's localName.
  • If the initiator is a CSS resource, the property returns "css".
  • If the initiator is a XMLHttpRequest object, the property returns "xmlhttprequest".
  • If the initiator is a PerformanceNavigationTiming object, the property returns an empty string ("").

Note: This feature is available in Web Workers.



Return value

A string representing the type of resource that initiated the performance event, as specified above.


function print_PerformanceEntries() {
  // Use getEntriesByType() to just get the "resource" events
  var p = performance.getEntriesByType("resource");
  for (var i=0; i < p.length; i++) {
function print_initiatorType(perfEntry) {
  // Print this performance entry object's initiatorType value
  var value = "initiatorType" in perfEntry;
  if (value)
    console.log("... initiatorType = " + perfEntry.initiatorType);
    console.log("... initiatorType = NOT supported");


Specification Status Comment
Resource Timing Level 1
The definition of 'initiatorType' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support43 Yes40 No30 No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support4343 Yes4230 No ?

Document Tags and Contributors

 Contributors to this page: ExE_Boss, chrisdavidmills, abbycar, rolfedh, AFBarstow
 Last updated by: ExE_Boss,