The end of 3rd Party Cookies — Chrome is Deprecating them in 2024
At the start of Jan 2024, Google announced and started phasing out 3rd party cookies. Companies need to start moving away from these asap as 1% of Chrome users are targeted, as well as Safari and Firefox users already prevent them.
On January 4, we’ll begin testing Tracking Protection, a new feature that limits cross-site tracking by restricting website access to third-party cookies by default. We’ll roll this out to 1% of Chrome users globally, a key milestone in our Privacy Sandbox initiative to phase out third-party cookies for everyone in the second half of 2024, subject to addressing any remaining competition concerns from the UK’s Competition and Markets Authority.
1% is 32 million users which isnt insignificant.
How 3rd Party Cookies work
Let’s consider an example scenario of how a third-party cookie might be implemented:
- User Visits a Website: User visits a hypothetical news website, www.example-news.com.
2. Includes of 3rd Party Content: The news website contains articles, images, and ads served by various third-party domains. One such 3rd party domain is www.advertising-network.com.
3. Request for 3rd Party Content: As the user loads a page on www.example-news.com, the browser sends requests to various servers, including www.advertising-network.com, to fetch the necessary content.
4. Response from the Advertising Network: The advertising network, www.advertising-network.com, responds to the browser’s request by delivering content, which may include an advertisement, along with instructions to set a third-party cookie.
5. Setting the 3rd Party Cookie: The instructions from www.advertising-network.com include code to set a third-party cookie on the user’s browser. The cookie might contain a unique identifier and information about the user’s interaction with the ad or the website.
<! - Example JavaScript code provided by the advertising network →
<script>
document.cookie = "thirdPartyUserId=ABC123; domain=.advertising-network.com;
path=/; expires=Sun, 01 Jan 2023 00:00:00 GMT;";
</script>In this example, the 3rd party cookie is named thirdPartyUserId and is set to expire on a specific date. The domain attribute specifies that the cookie is accessible to any subdomain under advertising-network.com.
6. Subsequent Requests: When the user visits another website that includes content from www.advertising-network.com (e.g., www.example-shopping.com), the browser automatically includes the 3rd party cookie associated with www.advertising-network.com in the request.
7. Tracking Across Websites: The advertising network can use the information stored in the third-party cookie to track the user’s interactions across different websites that include its content. This information is often used for targeted advertising.
Another example is Facebook where adding a like button or link back to Facebook will allow that site to send relevant information back to them about your visit and then Facebook can serve you targeted content based on that visit.
3rd Party Cookie Usage
There are a few main use cases for 3rd party cookies:
- Marketing
- Chat widgets
- Auth services
The majority of the impact felt will be by producers of the 3rd party cookies like AdTech companies. Facebook Pixel is an example which produces, among others, these 3rd party cookies which will be blocked.
How do I know if Im impacted
Google suggests blocking 3rd party cookies on your browser and testing what breaks.
- chrome://flags/#test-third-party-cookie-phaseout
2.
- Block 3rd party cookies: In Chrome, go to: chrome://settings/cookies.
1% of users will need to go to a different page: chrome://settings/trackingProtection
2. Open Dev Tools: Hit F12
3. Add the Issues tab: click on the ellipse -> More tools -> Issues
4. Browse to the URL you want to test: You will see under the Issues tab the text Reading cookie in cross-site context will be blocked in future Chrome versions. This means that you have 3rd party cookies on your site
