The PageTransitionEvent is fired when a document is being loaded or unloaded.
This interface also inherits properties from its parent, Event.
PageTransitionEvent.persisted Read only 
<!DOCTYPE html> <html> <body onpageshow="myFunction(event)"> </body> </html>
function myFunction(event) { 
    if (event.persisted) {
        alert("The page was cached by the browser");
    } else {
        alert("The page was NOT cached by the browser");
    }
}
 | Specification | Status | Comment | 
|---|---|---|
| HTML Living Standard The definition of 'PageTransitionEvent' in that specification. | Living Standard | Initial definition | 
| Desktop | ||||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
| Basic support | Yes | ? | Yes | ? | Yes | ? | 
| persisted | Yes | ? | Yes | ? | Yes | ? | 
| Mobile | |||||||
|---|---|---|---|---|---|---|---|
| Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
| Basic support | Yes | Yes | ? | Yes | Yes | ? | ? | 
| persisted | Yes | Yes | ? | Yes | Yes | ? | ? | 
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    https://developer.mozilla.org/en-US/docs/Web/API/PageTransitionEvent