Chrome's third-party cookie grace period provides a way for sites and services experiencing breakage to request additional time to move away from third-party cookies to alternative solutions. Eligible grace period participants will be granted continued access to third-party cookies for a limited time. Chrome plans to maintain the grace period at least until we introduce a new experience in Chrome that lets people make an informed choice about third-party cookies that applies across their web browsing.
To apply for access to the grace period, you must report features that will be broken by third-party cookie changes at goo.gle/report-3pc-broken. Breakage can be reported by a third-party, first-party (or a user).
Your application will be reviewed to ensure that the grace period exception is only used for site features that impact critical user journeys. To be eligible, sites must demonstrate functional breakage in user-facing journeys that are not related to advertising use cases. Chrome will institute checks to determine scripts and domains related to advertising. Applications are considered on a case-by-case basis.
Chrome will work with disconnect.me, an industry leader in internet privacy, and implement Disconnect's tracker protection lists to identify the scripts and domains categorized as advertising. Disconnect is already used by other browsers for similar purposes on the web.
We will apply the following process to ascertain grace period eligibility:
- If the third-party origin matches a known advertising domain, including if the origin matches an entry on the Disconnect advertising list, then the domain will not be eligible for the grace period. In general, entries on the list will match all subdomains below the specified origin. Some entries, however, include a path element. These more specific entries will match the given origin, but not subdomains.
- Steps to reproduce a broken user-facing experience must be provided. In particular, this should be an experience for the user operating the device where the cookie is stored, and not a user performing later analysis of data. If we cannot validate a broken user experience then the domain will not be eligible for the grace period.
- Otherwise the domain will be eligible.
Disable grace period for testing
To test with the grace period disabled, even if your site has been granted access, set chrome://flags/#tpcd-metadata-grants to Disabled.
Learn more: Chrome flags for testing.
Opt-out mechanism
Chrome is also providing a mechanism to allow sites to opt out of the grace period for a percentage of users. The opt-out mechanism will enable sites to run their own staged rollouts to help them transition away from relying on the grace period and move towards long-term solutions.
Learn more: An opt-out mechanism for the third-party cookie deprecation trial grace period.