Support in current browsers

Checked against the current browser versions recorded in MDN browser data 8.0.7.

BrowserMinimumOutcomeReason
Chrome150WorksEvery required mapped BCD feature is available without a recorded qualification.
Edge150WorksEvery required mapped BCD feature is available without a recorded qualification.
Firefox152WorksEvery required mapped BCD feature is available without a recorded qualification.
Safari26.5WorksEvery required mapped BCD feature is available without a recorded qualification.
Chrome for Android150WorksEvery required mapped BCD feature is available without a recorded qualification.
Firefox for Android152WorksEvery required mapped BCD feature is available without a recorded qualification.
Safari on iOS26.5WorksEvery required mapped BCD feature is available without a recorded qualification.
Android WebView150WorksEvery required mapped BCD feature is available without a recorded qualification.
Samsung Internet29.0WorksEvery required mapped BCD feature is available without a recorded qualification.

What this feature can and cannot do

Helps protect against

  • Uncontrolled cross-origin embedding
  • Cross-origin isolation gaps

Does not guarantee

  • Application authorisation
  • All data leakage
  • Resources that are already same-origin

What you need before using it

  • Compatible embedded resources
  • Usually COOP for cross-origin isolation

Fallback to keep in place

Keep sensitive operations independent of cross-origin isolation and review embedded resource origins.