PSA: Updates on Chrome-facilitated Cookie Deprecation Testing
Nan Lin
Contact emails
jka...@chromium.org, k...@google.com, lin...@chromium.org
Documentation
https://privacysandbox.google.com/private-advertising/setup/web/chrome-facilitated-testing
Link to entry on the Chrome Platform Status
https://chromestatus.com/feature/5189079788683264
Platforms
Windows, Mac, Linux, Chrome OS, and Android (not Android WebView)
Summary
With the recent decision to retire many of the Privacy Sandbox technologies, we wanted to provide an update on the Chrome-facilitated testing experiment.
Cookie Deprecation Labels: The Sec-Cookie-Deprecation HTTP header and the navigator.cookieDeprecationLabel JavaScript API will be deprecated. The experiment will conclude with the M142 release.
Mode B 1% - Users in the 1% who previously had third party cookies disabled as part of the Chrome-facilitated testing ("Mode B") will have third party cookies re-enabled. These users will be notified of this change via banner in their browser. We expect this work to likely finish up by the end of 2025.
The impact on developers is expected to be minimal. The cookie deprecation labels are only available for a subset of users and must be requested. To detect third-party cookie availability in Chrome, we recommend using Storage Access Headers as a replacement for the expiring labels.