Heads Up Publishers: Third-Party Cookie Phase Out Starts Soon

In an October 11th announcement on the Chrome for Developers blog, Google provided an important update on the timeline for phasing out third-party cookies in Chrome. 

Publishers have long expected this change, with the first announcement of the impending deprecation shaking the publishing sector in 2020. While Google has previously delayed the rollout of the cookie deprecation in Chrome, the recent update makes clear the rollout will begin in 2024. Publishers relying on these cookies need to take action now to prepare.

According to Google, here’s what they should do:

Audit Cookie Usage

The first step is to identify all instances where your sites use cookies. Check code changes from early 2020 when preparing for Chrome’s original cookie restrictions. Use Chrome DevTools to inspect cookies on network requests and audit third-party cookies. Confirm third-party partners like analytics tools have migration plans to replace cookie-dependent services. 

Start Testing for Breakage Now  

Use Chrome flags to simulate the phase out and identify where things break. The Issues panel will flag affected cookies. Add third-party cookie blocking to your test suites. Note failures that only occur when cookies are blocked. Fix issues where embedded third-party content fails without cookie access — report problems to Google.

Evaluate Alternatives to Mitigate Impact

For isolated third-party embeds, use Partitioned cookies to allow cookie access on a per-site basis. For related sites like regional/brand domains, try Related Website Sets for cross-site cookie access. Migrate other uses like ads and identity to Chrome’s Privacy Sandbox APIs built for this purpose. Use the Storage Access API for cross-site embeds like social sharing widgets that require user interaction.

Adapex regularly tracks the effectiveness of alternate identity solutions and partners with publishers to enable them to capitalize on the cookieless transition. Our Identity Insights card is a powerful tool in giving an overview of ID coverage as the industry and publishers continue to evaluate the alternative IDs that are right for them. 

Leverage Google’s Temporary Opt-In Trial

Google will offer a temporary opt-in trial to delay losing third-party cookies for non-ad scenarios affecting critical user flows. Details are forthcoming, but publishers can request extended time if cookie loss significantly impacts key journeys. This provides breathing room to implement alternatives before full enforcement.

Report Breakage to Get Support

Use Google’s breakage tracker to report any issues losing cookies causes for your sites or services. Flag scenarios not covered by current mitigations so Google can provide help. Ask questions on implementation in Google’s developer support channels.

Google’s update makes clear the third-party cookie phase out is nearing. To prepare, audit cookie usage, rigorously test, adopt alternatives, and engage Google for support. 

Remember, while the deprecation of the third-party cookie is a substantive change, the publishers that adapt can differentiate themselves and take control of their audience and data. The media sector belongs to the publishers that rise to the occasion to put privacy first and redefine our relationships with data.