Two primary goals: - Be able to embed iframes that have same-origin as other frames in the frame tree but not be able to directly script them. - Have a same-origin iframe with other iframes be in a separate event loop.


Allowing cross-document DOM access has made the web very complicated. Wouldn't it be nice if individual pages could opt themselves or their frames into a simplier mode which didn't allow cross-document access?



Specification link

Specification being incubated in a Community Group

Status in Chromium


No longer pursuing (tracking bug)

Consensus & Standardization

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


Last updated on 2021-06-09