The PerformanceObserver() constructor creates a new PerformanceObserver object with the given observer callback. The observer callback is invoked when performance entry events are recorded for the entry types that have been registered, via the observe() method.
PerformanceObserver()
Syntax
new PerformanceObserver(callback);
Parameters
-
callback -
A
PerformanceObserverCallbackcallback that will be invoked when observed performance events are recorded. When the callback is invoked, its first parameter is a list of performance observer entries and the second parameter is theobserverobject.
Return value
A new PerformanceObserver object which will call the specified callback when observed performance events occur.
Examples
var observer = new PerformanceObserver(function(list, obj) { var entries = list.getEntries(); for (var i=0; i < entries.length; i++) { // Process "mark" and "frame" events } }); observer.observe({entryTypes: ["mark", "frame"]}); function perf_observer(list, observer) { // Process the "measure" event } var observer2 = new PerformanceObserver(perf_observer); observer2.observe({entryTypes: ["measure"]});
Specifications
Browser compatibility
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
PerformanceObserver |
52
|
79
|
57
|
No
|
39
|
11
|
52
|
52
|
57
|
41
|
11
|
6.0
|
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https://developer.mozilla.org/en-US/docs/Web/API/PerformanceObserver/PerformanceObserver
