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This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The PerformanceObserver interface is used to observe performance measurement events and be notified of new performance entries as they are recorded in the browser's performance timeline.
Note: this interface is exposed to Window and Worker.
Constructor
PerformanceObserver()- Creates a
PerformanceObserverobject.
Methods
PerformanceObserver.observe()- Specifies the set of
entry typesto observe. The performance observer's callback function will be invoked when aperformance entryis recorded for one of the specifiedentryTypes PerformanceObserver.disconnect()- Stops the performance observer callback from receiving
performance entries.
Example
function perf_observer(list, observer) {
// Process the "measure" event
}
var observer2 = new PerformanceObserver(perf_observer);
observer2.observe({entryTypes: ["measure"]});
Specifications
| Specification | Status | Comment |
|---|---|---|
| Performance Timeline Time Level 2 The definition of 'PerformanceObserver' in that specification. |
Editor's Draft | Initial definition of PerformanceObserver interface. |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support | 52.0 | 49 (49)[1] | No support | 39 | No support |
| Feature | Android | Android Webview | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|---|---|
| Basic support | No support | No support | 49.0 (49)[1] | No support | No support |
39 |
No support | 52.0 |
[1] Only activated in Nightly builds. Controlled by the dom.enable_performance_observer preference.