Fenced frames are frames isolated from their embedding page. More details in the explainer here: https://github.com/shivanigithub/fenced-frame


Third party iframes can communicate with their embedding page using mechanisms such as postMessage, attributes (e.g., size and name), and permissions. A number of recently proposed APIs (such as Interest group based advertising, Conversion Lift Measurements) provide some degree of unpartitioned storage to embedded documents. Once third-party cookies have been removed, such documents should not be allowed to communicate with their embedders, else they will be able to join their cross-site user identifiers with the embedder’s, which would allow for user tracking. This explainer proposes a new form of embedded document, called a fenced frame, that these new APIs can use to isolate themselves from their embedders, preventing cross-site recognition.

Status in Chromium


No active development (tracking bug)

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • No signal
  • No signal
  • No signals


Last updated on 2021-12-10