Chrome

Current status

The Chrome browser doesn’t currently have mechanisms designed specifically for tracking protection.

The privacy-sandbox Chromium project promises initiatives related to tracking prevention, and Chrome has publicly stated intention to making third-party cookies obsolete by 2022.

Classification of “known trackers”

Chrome does not classify classify trackers or domains for the purposes of tracking protection.

Third-party cookies

Chrome does not restrict the use of third-party cookies.

First-party cookies

Chrome does not restrict the use of first-party cookies.

Other third-party storage

Chrome does not restrict the use of other browser storage in third-party context.

Other first-party storage

Chrome does not restrict the use of other browser storage in first-party context.

CNAME cloaking

No protections against CNAME cloaking.

Referrer

Chrome 85 sets the default referrer policy to strict-origin-when-cross-origin. This means that for cross-origin requests (e.g. sub.domain.com to othersub.domain.com, or sub.domain.com to sub.otherdomain.com) the referer HTTP header and document.referrer JavaScript API are truncated to show just the origin of the website making the request. Thus a page such as https://www.domain.com/some-page?param=value would show up just as https://www.domain.com in the referrer records.

Other

On macOS Chrome, the version number in the User Agent string is frozen to 10_15_7 to fix compatibility issues with upgrading to macOS version 11+ (Big Sur). This has obvious privacy implications as well, as the platform version is no longer useful for fingerprinting purposes.

Sample User Agent string when running Chrome 90.0.4430.212 on macOS 11.3.1:
"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"