Chrome set a two-year clock on third-party cookies

The signal

In advertising, Google's Chromium team announced on 14 January 2020, in a post titled Building a more private web: A path towards making third party cookies obsolete, that it intended to phase out support for third-party cookies in Chrome, stating: "Our intention is to do this within two years." The post, credited to Justin Schuh, then Director of Chrome Engineering, framed the change as contingent on the Privacy Sandbox proposals, announced the previous August, first addressing the needs of users, publishers and advertisers, and promised the first origin trials, starting with conversion measurement, by the end of that year.

The evidence

The post is explicit about sequencing: a related but separate change, treating cookies without a SameSite label as first-party only and requiring third-party cookies to be served over HTTPS, was said to begin in February 2020, ahead of and distinct from the full phase-out. The post also draws its own contrast with other browsers that had already blocked third-party cookies outright, arguing that a blunt block "can negatively impact both users and the web ecosystem" by pushing sites toward fingerprinting, a workaround the post frames as reducing user privacy rather than protecting it. That is Chrome's own justification for a gradual, standards-based approach rather than an immediate block, not an independent assessment of whether the approach worked.

Timeframe and confidence

This is an editorial reading: the January 2020 post is a firm, dated statement of intent from the company controlling the browser with the largest market share, which makes the announcement itself a significant fact regardless of what followed. It is not, on its own, evidence that the two-year timeline was realistic; a target stated in a company blog post is a forecast of the company's own plan, not a measurement of anything that had already happened.

What would change the reading

Google's own Privacy Sandbox site, showing a last-updated date of 17 October 2025 as retrieved on 16 September 2026, already indicates the answer for this specific claim: it states that some Privacy Sandbox technologies are being phased out, language reflecting a project that has been revised more than once since 2020. Tracking each revision's stated date and reason, rather than only the original 2020 target, would show whether delays stemmed from technical readiness, regulatory pressure or advertiser pushback.

• When a company sets a multi-year technical deadline in a blog post, what enforcement mechanism, if any, holds it to that date?
• How many times has a stated timeline been revised, and does each revision cite a new reason or repeat the previous one?
• Does a platform's own justification for a gradual approach hold up against the outcomes of browsers that took the blunter path it criticised?

The two-year promise made in January 2020 is a clearly dated forecast, not a delivered outcome, and the platform's own later pages already show that forecast being revised rather than met on schedule.

Source trail

1. Building a more private web: A path towards making third party cookies obsoleteblog.chromium.org · Source publication: 2020-01-14 · Retrieved 2026-09-16

   Original announcement of the 'within two years' third-party cookie phase-out intention and its Privacy Sandbox rationale.

2. Privacy Sandboxprivacysandbox.google.com · Source publication: not established · Retrieved 2026-09-16

   Living page showing the current, revised status of Privacy Sandbox technologies as of its last update.

Read across the evidence

• Chrome’s cookie plan became a moving planning assumption
• Digital ad revenue grew 7.3% to $225 billion in 2023
• Apple's tracking prompt reshaped how advertisers target

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