files/en-us/web/api/pagetransitionevent/index.md
{{APIRef("HTML DOM")}}
The PageTransitionEvent event object is available inside handler functions for the pageshow and pagehide events, fired when a document is being loaded or unloaded.
{{InheritanceDiagram}}
PageTransitionEvent object.This interface also inherits properties from its parent, {{domxref("Event")}}.
window.addEventListener("pageshow", (event) => {
if (event.persisted) {
alert("The page was cached by the browser");
} else {
alert("The page was NOT cached by the browser");
}
});
{{Specifications}}
{{Compat}}