CHIPS (Partitioned Cookies)

CHIPS lets a third-party cookie be stored in a separate jar for each site that loads it, so it works on that site but cannot follow the user anywhere else.

Browsers block third-party cookies that track people across sites. CHIPS, short for Cookies Having Independent Partitioned State, is the sanctioned exception: you add the Partitioned attribute to a cookie and the browser keeps a separate copy per top-level site.

Say you run a live-chat widget embedded on shopA.com and shopB.com. With CHIPS the cookie it sets on shopA is kept apart from the one on shopB, so the chat session stays logged in on each site while the widget cannot stitch the two visits into one profile. Open your own site's DevTools, go to the Application tab, Cookies, and look for the Partitioned column.

A partitioned cookie cannot be shared across your own domains either. If you were deliberately using one third-party cookie to recognize a returning user across shopA and shopB, CHIPS breaks that on purpose, and you will need a different method for genuine cross-site sign-in.

CHIPS is the piece of the cookie world that survived the cull, precisely because it cannot track.