PerformanceObserver

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 PerformanceObserver object.

Methods

PerformanceObserver.observe()

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

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

[1] Only activated in Nightly builds. Controlled by the dom.enable_performance_observer preference.