NotRestoredReasons: reasons property

{{APIRef("Performance API")}}{{SeeCompatTable}}

The reasons read-only property of the {{domxref("NotRestoredReasons")}} interface returns an array of {{domxref("NotRestoredReasonDetails")}} objects, each representing a reason why the navigated page was blocked from using the back/forward cache ({{Glossary("bfcache")}}).

Value

An array of {{domxref("NotRestoredReasonDetails")}} objects. See Blocking reasons for a list of the possible blocking reasons.

If the document is in a cross-origin {{htmlelement("iframe")}}, reasons will return null, but the parent document may show a reason of "masked" if any <iframe>s blocked bfcache usage for the top-level frame.

Examples

See Monitoring bfcache blocking reasons for examples.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• Monitoring bfcache blocking reasons
• {{domxref("PerformanceNavigationTiming.notRestoredReasons")}}