PerformanceTiming: unloadEventStart property

Deprecated

Avoid using this feature in new projects. This feature is supserseded by the PerformanceNavigationTiming API. This feature may be a candidate for removal from web standards or browsers.

Consider using the following features instead: Performance or Navigation timing.

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Warning: This interface of this property is deprecated in the Navigation Timing Level 2 specification. Please use the PerformanceNavigationTiming interface instead.

The legacy PerformanceTiming.unloadEventStart read-only property returns an unsigned long long representing the moment, in milliseconds since the UNIX epoch, the unload event has been thrown. If there is no previous document, or if the previous document, or one of the needed redirects, is not of the same origin, the value returned is 0.