What is CHIPS (Cookies Having Independent Partitioned State), and how does it stop cross-site tracking while keeping third-party features working?
CHIPS partitions third-party cookies by the top-level site, so the same third-party cookie on news.example is separate from the one on retail.example — making cross-site tracking technically impossible while preserving legitimate features.
* CHIPS stores third-party cookies in per-top-level-site jars that cannot be linked. *
The problem: traditional third-party cookies are not bound to the top-level site, so an embedded analytics.com cookie is the same across every site that embeds it — perfect for cross-site profiling.
The CHIPS solution: cookies are stored in a partitioned jar keyed by the top-level site. A cookie from analytics.com while you're on retail.example is a different cookie than the one from analytics.com on news.example.
The privacy win:
- Cross-site tracking becomes technically impossible (the tracker can't link the two partitions)
- Legitimate third-party functions — support chat, payment widgets, embedded maps — still work, because they only need state within a single top-level site
CHIPS is part of Google's Privacy Sandbox. (Note: several Privacy Sandbox technologies have since been scaled back or discontinued.)
Go deeper:
Privacy Sandbox — CHIPS (Wikipedia) — CHIPS as an implemented partitioned-cookie proposal.