What Is the Privacy Sandbox and How Does It Replace Cookies in Chrome

The Privacy Sandbox was Google's plan to remove third-party cookies from Chrome and replace them with new browser tools for advertising that revealed less about individual people. It didn't work out: Google kept third-party cookies, and in October 2025 it announced it was retiring most of the Privacy Sandbox.

What it was meant to do

Third-party cookies let ad companies follow you from site to site. Google proposed handling the main advertising jobs inside the browser instead:

• Topics: Chrome guessed broad interests from your browsing and shared a few with sites. See the Topics API explained.
• Protected Audience: ads based on sites you visited, with the auction run in your browser.
• Attribution Reporting: measuring whether ads led to purchases without tracking individuals.
• Other tools for logins, fraud prevention and related sites.

What happened

• Google announced the project in 2019 and delayed the removal of third-party cookies several times.
• Regulators, especially the UK's Competition and Markets Authority, examined whether it would give Google an unfair advantage.
• Advertisers said the new tools didn't work as well, and privacy groups said they still enabled tracking.
• Google decided to keep third-party cookies, then in October 2025 said it would retire Topics, Protected Audience, Attribution Reporting and most other parts because few companies used them.

What's staying

A few pieces survive because they're useful beyond advertising, including CHIPS (cookies kept separate for each site an embed appears on), FedCM (for "Sign in with" buttons) and Private State Tokens (for fraud prevention).

What this means for you

Third-party cookies still work in Chrome unless you block them. Safari and Firefox already block most of them by default. See the third-party cookie timeline.

How to limit tracking in Chrome

• Settings → Privacy and security → Third-party cookies → Block third-party cookies.
• Check Settings → Privacy and security → Ad privacy and turn off what's still listed.
• Reject cookie banners. Cookie Auto-Reject clicks "Reject all" for you on many sites.
• Learn about tracking that doesn't use cookies, such as browser fingerprinting.

Ghost Browser adds random background visits, so any profile built from your browsing is less accurate.