Web/API/PerformanceObserverEntryList/getEntriesByType

The getEntriesByType() method of the PerformanceObserverEntryList returns a list of explicitly observed performance entry objects for a given performance entry type. The list's members are determined by the set of entry types specified in the call to the observe() method. The list is available in the observer's callback function (as the first parameter in the callback).

This method is exposed to Window and Worker interfaces.

Syntax

entries = list.getEntriesByType(type);

Parameters

type: The type of entry to retrieve such as "frame". The valid entry types are listed in PerformanceEntry.entryType.

Return value

A list of explicitly observed PerformanceEntry objects that have the specified type. The items will be in chronological order based on the entries' startTime. If no objects have the specified type, or no argument is provided, an empty list is returned.

Example

function print_perf_entry(pe) {
  console.log("name: "        + pe.name      +
              "; entryType: " + pe.entryType +
              "; startTime: " + pe.startTime +
              "; duration: "  + pe.duration);
}

// Create observer for all performance event types
var observe_all = new PerformanceObserver(function(list, obs) {
  var perfEntries;

  // Print all entries
  perfEntries = list.getEntries();
  for (var i=0; i < perfEntries.length; i++) {
    print_perf_entry(perfEntries[i]);
  }

  // Print entries named "Begin" with type "mark"
  perfEntries = list.getEntriesByName("Begin", "mark");
  for (var i=0; i < perfEntries.length; i++) {
    print_perf_entry(perfEntries[i]);
  }

  // Print entries with type "mark"
  perfEntries = list.getEntriesByType("mark");
  for (var i=0; i < perfEntries.length; i++) {
    print_perf_entry(perfEntries[i]);
  }
});
// subscribe to all performance event types
observe_all.observe({entryTypes: ['frame', 'mark', 'measure', 'navigation', 'resource', 'server']});

var observe_frame = new PerformanceObserver(function(list, obs) {
  var perfEntries = list.getEntries();
  // Should only have 'frame' entries
  for (var i=0; i < perfEntries.length; i++) {
    print_perf_entry(perfEntries[i]);
  }
});
// subscribe to only the 'frame' event
observe_frame.observe({entryTypes: ['frame']});

Specifications

Specification	Status	Comment
Performance Timeline Level 2The definition of 'getEntriesByType()' in that specification.	Candidate Recommendation	Initial definition of `getEntriesByType()` method.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`getEntriesByType`	Chrome Full support 52	Edge Full support ≤79	Firefox Full support 57	IE No support No	Opera Full support 39	Safari No support No	WebView Android No support No	Chrome Android Full support 52	Firefox Android Full support 57	Opera Android Full support 41	Safari iOS No support No	Samsung Internet Android Full support 6.0

Legend

Full support: Full support
No support: No support

PerformanceObserverEntryList.getEntriesByType() by Mozilla Contributors is licensed under CC-BY-SA 2.5.