Location: ancestorOrigins property
Baseline
2026
Newly available
Since February 2026, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.
The ancestorOrigins read-only
property of the Location interface is a static
DOMStringList containing, in reverse order, the origins of all ancestor
browsing contexts of the document associated with the given Location
object.
You can use location.ancestorOrigins in the script for a document to
determine, for example, whenever the document is being framed by a site which you don't
expect it to be framed by. You can also use it to vary the behavior of the document
based on what site or list of sites is framing it.
Note:
The referrerpolicy attribute of an embedding <iframe> affects this list. Setting referrerpolicy to no-referrer, or to same-origin when the framed document is cross-origin, redacts the origin of the document containing the <iframe> from the ancestorOrigins list of the framed document. The origin is replaced with an opaque origin, which serializes as "null".