CookieDeprecation — 3p-Cookie Sunset + Privacy Sandbox Readiness
22 third-party cookie use cases × Chrome 3p-cookie deprecation + Privacy Sandbox APIs (Topics, Protected Audience, Attribution Reporting, Storage Access, FedCM, CHIPS). Per use case: current implementation, replacement API, readiness state, Safari/Firefox fallback (already blocking).
What it is
The migration register for the 3p-cookie sunset. Most teams know it’s coming; few have inventoried which features depend on 3p cookies + which Privacy Sandbox API replaces each.
What’s in it
- 22 use cases × 11 categories (auth, attribution, advertising, analytics, fraud, embed, experimentation, commerce, marketing, consent)
- Per case: current 3p-cookie impl, Privacy Sandbox replacement (Topics / Protected Audience / Storage Access / FedCM / CHIPS), readiness state (migrated / in-flight / at-risk / no-replacement)
- Worst-offender findings: remarketing audience (no Privacy Sandbox replacement on Safari/FF), 3p cookie-based session restoration (intentional anti-pattern), cross-site abandoned-cart retargeting (limited to logged-in customers)
Why this shape
Chrome 3p-cookie deprecation timeline + Safari ITP + Firefox ETP all converge on: 3p cookies are gone or going. Privacy Sandbox introduces 6+ replacement APIs each suited to different use cases.
How it ships
Single HTML file, ~12KB. Zero dependencies. 22 use cases × per-case migration plan in 100 lines of vanilla JavaScript.