files/en-us/web/api/performancenavigationtiming/index.md
{{APIRef("Performance API")}}
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 {{domxref("PerformanceResourceTiming")}} and {{domxref("PerformanceEntry")}}.
{{InheritanceDiagram}}
The following diagram shows all of the timestamp properties defined in PerformanceNavigationTiming.
This interface extends the following {{domxref('PerformanceEntry')}} properties by qualifying and constraining them as follows:
"navigation".0.This interface also extends the following {{domxref('PerformanceResourceTiming')}} properties by qualifying and constraining them as follows:
"navigation".The interface also supports the following properties:
readyState to "complete".DOMContentLoaded event handler completes.DOMContentLoaded event handler starts.readyState to "interactive".load event handler completes.load event handler starts."navigate", "reload", or "back_forward".unload event handler completes.unload event handler starts.PerformanceNavigationTiming object.{{Specifications}}
{{Compat}}