PerformanceEntry

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.

Note: This feature is available in Web Workers.

The PerformanceEntry object encapsulates a single performance metric that is part of the browser's performance timeline.

The Performance API offers built-in metrics which are specialized subclasses of PerformanceEntry. This includes entries for resource loading, event timing, and more.

A performance entry can also be created by calling the Performance.mark() or Performance.measure() methods at an explicit point in an application. This allows you to add your own metrics to the performance timeline.

The PerformanceEntry instances will always be one of the following subclasses:

Instance properties

PerformanceEntry.name Read only

A string representing the name for a performance entry. The value depends on the subtype.

PerformanceEntry.entryType Read only

A string representing the type of performance metric. For example, "mark" when PerformanceMark is used.

PerformanceEntry.startTime Read only

A DOMHighResTimeStamp representing the starting time for the performance metric.

PerformanceEntry.duration Read only

A DOMHighResTimeStamp representing the duration of the performance entry.

Instance methods

PerformanceEntry.toJSON()

Returns a JSON representation of the PerformanceEntry object.

Example

Working with performance entries

The following example creates PerformanceEntry objects that are of the types PerformanceMark and PerformanceMeasure. The PerformanceMark and PerformanceMeasure subclasses inherit the duration, entryType, name, and startTime properties from PerformanceEntry and set them to their appropriate values.

js
// Place at a location in the code that starts login
performance.mark("login-started");

// Place at a location in the code that finishes login
performance.mark("login-finished");

// Measure login duration
performance.measure("login-duration", "login-started", "login-finished");

function perfObserver(list, observer) {
  list.getEntries().forEach((entry) => {
    if (entry.entryType === "mark") {
      console.log(`${entry.name}'s startTime: ${entry.startTime}`);
    }
    if (entry.entryType === "measure") {
      console.log(`${entry.name}'s duration: ${entry.duration}`);
    }
  });
}
const observer = new PerformanceObserver(perfObserver);
observer.observe({ entryTypes: ["measure", "mark"] });

Specifications

Specification
Performance Timeline
# dom-performanceentry

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
PerformanceEntry
duration
entryType
name
startTime
toJSON
Available in workers

Legend

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Full support
Full support
Partial support
Partial support
Requires a vendor prefix or different name for use.
Has more compatibility info.