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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.


Creates a PerformanceObserver object.


Specifies the set of entry types to observe. The performance observer's callback function will be invoked when a performance entry is recorded for one of the specified entryTypes
Stops the performance observer callback from receiving performance entries.
Returns the current list of performance entries stored in the performance observer, emptying it out.


function perf_observer(list, observer) { 
   // Process the "measure" event 
var observer2 = new PerformanceObserver(perf_observer); 
observer2.observe({entryTypes: ["measure"]});


Specification Status Comment
Performance Timeline Level 2
The definition of 'PerformanceObserver' in that specification.
Candidate Recommendation Initial definition of PerformanceObserver interface.

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 52 57 (57) No support 39 11
Available on workers 62 ? ? 49 ?
Feature Android Webview Chrome for Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support No support 52 57.0 (57) No support


No support
Available on workers No support 62 ? ?



Document Tags and Contributors

Contributors to this page: chrisdavidmills, jpmedley, stefanjudis, teoli, rolfedh, AFBarstow
Last updated by: chrisdavidmills,