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.
Syntax
var observer = new PerformanceObserver(callback);
Parameters
callback
- A
PerformanceObserverCallback
callback 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 theobserver
object.
Return value
A new PerformanceObserver
object which will call the specified callback
when observed performance events occur.
Example
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
Specification | Status | Comment |
---|---|---|
Performance Timeline Level 2 The definition of 'PerformanceObserver()' in that specification. |
Candidate Recommendation | Initial definition of PerformanceObserver() constructor. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
PerformanceObserver() constructor | Chrome Full support 52 | Edge Full support ≤79 | Firefox Full support 57 | IE No support No | Opera Full support 39 | Safari Full support 11 | WebView Android Full support 52 | Chrome Android Full support 52 | Firefox Android Full support 57 | Opera Android Full support 41 | Safari iOS Full support 11 | Samsung Internet Android Full support 6.0 |
Legend
- Full support
- Full support
- No support
- No support