The initiatorType 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 ("").

This property is Read only .



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
The definition of 'initiatorType' in that specification.
Editor's Draft Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support. 43 40 10 32 No support
Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support. 4.4 42 ? 10.0 32 No support


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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Property Reference Web Performance