v135 · privacy / ads

Beacon Policy Explorer

Configure the three parties in an automatic beacon flow — publisher, ad-tech, and reporting endpoint — and see which cross-origin data combinations are permitted by Chrome 135 policy. Toggle crossOriginExposed, destination types, and event triggers to generate the exact setReportEventDataForAutomaticBeacons() call.

checking Fenced Frames API…

Automatic beacons let fenced frame content (ads) send measurement data when certain events occur (navigation, click-through) without exposing user identity. Chrome 135 adds cross-origin data support: the publisher can attach extra data that the buyer/reporter receives in the beacon payload, even across origin boundaries, as long as both parties opt in.

Three-party setup

Publisher

news.example

Embeds the fenced frame. Sets beacon data via setReportEventDataForAutomaticBeacons() with crossOriginExposed: true/false.

Ad-tech (fenced frame)

ads.example

Content inside the fenced frame. Registers destinations via fence.setReportingDestination() and triggers beacons on navigation.

Reporting endpoint

report.adtech.example

Receives the POST beacon. May be same-origin as the ad-tech or a third-party measurement service.

Policy configuration

Beacon event trigger

Reporting destination

crossOriginExposed: true

once (send once then clear)

Cross-origin data policy matrix

crossOriginExposed	Destination type	Publisher data included?	Notes

Beacon simulation log

Click "Simulate beacon" to run a beacon dispatch.

Generated API call

Configure above and click Simulate beacon.