PerformanceNavigationTiming

The PerformanceNavigationTiming interface provides methods and properties to store and retrieve metrics regarding the browser's document navigation events. For example, this interface can be used to determine how much time it takes to load or unload a document.

Only the current document is included in the performance timeline, so there is only one PerformanceNavigationTiming object in the performance timeline. It inherits all of the properties and methods of PerformanceResourceTiming and PerformanceEntry.

PerformanceEntry PerformanceResourceTiming PerformanceNavigationTiming

The following diagram shows all of the timestamp properties defined in PerformanceNavigationTiming.

Timestamp diagram listing timestamps in the order in which they are recorded for the fetching of a document

Instance properties

This interface extends the following PerformanceEntry properties by qualifying and constraining them as follows:

PerformanceEntry.entryType Read only

Returns "navigation".

PerformanceEntry.name Read only

Returns the document's URL.

PerformanceEntry.startTime Read only

Returns a DOMHighResTimeStamp with a value of "0".

PerformanceEntry.duration Read only

Returns a timestamp that is the difference between the PerformanceNavigationTiming.loadEventEnd and PerformanceEntry.startTime properties.

This interface also extends the following PerformanceResourceTiming properties by qualifying and constraining them as follows:

PerformanceResourceTiming.initiatorType Read only

Returns "navigation".

The interface also supports the following properties:

PerformanceNavigationTiming.activationStart Read only

A DOMHighResTimeStamp representing the time between when a document starts prerendering and when it is activated.

PerformanceNavigationTiming.criticalCHRestart Read only

A DOMHighResTimeStamp representing the time at which the connection restart occurred due to Critical-CH HTTP response header mismatch.

PerformanceNavigationTiming.domComplete Read only

A DOMHighResTimeStamp representing the time immediately before the user agent sets the document's readyState to "complete".

PerformanceNavigationTiming.domContentLoadedEventEnd Read only

A DOMHighResTimeStamp representing the time immediately after the current document's DOMContentLoaded event handler completes.

PerformanceNavigationTiming.domContentLoadedEventStart Read only

A DOMHighResTimeStamp representing the time immediately before the current document's DOMContentLoaded event handler starts.

PerformanceNavigationTiming.domInteractive Read only

A DOMHighResTimeStamp representing the time immediately before the user agent sets the document's readyState to "interactive".

PerformanceNavigationTiming.loadEventEnd Read only

A DOMHighResTimeStamp representing the time immediately after the current document's load event handler completes.

PerformanceNavigationTiming.loadEventStart Read only

A DOMHighResTimeStamp representing the time immediately before the current document's load event handler starts.

PerformanceNavigationTiming.notRestoredReasons Read only

A NotRestoredReasons object providing report data on reasons why the current document was blocked from using the back/forward cache (bfcache) on navigation.

PerformanceNavigationTiming.redirectCount Read only

A number representing the number of redirects since the last non-redirect navigation in the current browsing context.

PerformanceNavigationTiming.type Read only

A string representing the navigation type. Either "navigate", "reload", "back_forward" or "prerender".

PerformanceNavigationTiming.unloadEventEnd Read only

A DOMHighResTimeStamp representing the time immediately after the current document's unload event handler completes.

PerformanceNavigationTiming.unloadEventStart Read only

A DOMHighResTimeStamp representing the time immediately before the current document's unload event handler starts.

Instance methods

PerformanceNavigationTiming.toJSON()

Returns a JSON representation of the PerformanceNavigationTiming object.

Specifications

Specification
Navigation Timing Level 2
# sec-PerformanceNavigationTiming

Browser compatibility

BCD tables only load in the browser

See also