3P cookie
Third-party cookie
A cookie set by a domain other than the one being visited, historically used for cross-site tracking and retargeting. Google abandoned its plan to remove them from Chrome in 2024 (confirmed in 2025), but their effectiveness is declining anyway: Safari and Firefox block them, ITP shortens them, and opt-outs are rising.
- Why it matters
- The myth “third-party cookies are dead” is false — but “everything's fine” isn't true either. They're alive but unreliable. That's why strategy shifts to first-party, not because they vanished.
Related terms
“3P cookie” is part of Glossary · Tracking & data — part of the Atlas, Websem's reference of AI search, marketing and data terms.