What Chrome’s Elimination of Third-Party Cookies Means for Meta Advertisers

On January 4, Google began its test to phase out third-party cookies, with the completion expected in the second half of 2024. What does this development mean for Meta advertisers?

I am not a cookie expert. I wish I were. But I decided to immerse myself in as much of this cookie news as possible to help understand — both for my advertising efforts and yours — whether this is something to worry about. And if there is, what we should do about it.

There’s a lot happening here. It also appears that there is a reasonable level of unknown as well. I’ll do my best to highlight what is known while also being clear when I’m just not sure — and maybe no one’s sure — about how this will roll out or impact Meta advertisers.

In this post, we’ll cover the following:

  1. What are cookies?
  2. Google’s Tracking Protection and third-party cookie phaseout
  3. Google’s replacement
  4. What Apple and Safari have already done
  5. How this impacts Meta advertisers
  6. What you should do
  7. Remaining questions
  8. Resources

What Are Cookies?

Cookies are small pieces of data or text that are used to store information on web browsers. Their purpose ranges from helpful (keeping you logged in or personalizing your experience on a website) to sinister (digital fingerprinting). And of course, plenty of gray in between.

Also understand that there are first-party and third-party cookies. First-party cookies are stored by the website itself. Third-party cookies are stored by a separate service that tracks users across multiple websites or devices.

The focus here is on third-party cookies. First-party cookies are not currently at risk.

Google’s Tracking Protection

Google’s Tracking Protection initiative is part of their Privacy Sandbox for the Web. The long-term goal is to eliminate all third-party cookies from Chrome browsers by the end of 2024.

On January 4, 2024, Tracking Protection rolled out globally to 1% of Chrome users via desktop and Android as an initial test. While 1% may not sound like much, Gizmodo estimates this is about 30 Million people, with 60% of all internet users on Chrome.

If you are part of this test, you will see the following notification in your browser…

Chrome Tracking Protection

Tracking Protection restricts website access to third-party cookies by default, though with caveats. If Chrome detects that a website requires third-party cookies to function (difficulties loading and displaying content), you may be prompted to temporarily re-enable them.

According to Google’s public timeline, this initial 1% test will run through the first half of the year, with the complete elimination of third-party cookies happening by the end of 2024.

3PC Testing Timeline

Google’s Replacement

Of course, Google’s not planning to completely eliminate third-party cookies without some sort of replacement. These cookies are important for advertisers and publishers, after all.

Privacy Sandbox for the Web will phase out third-party cookies by using the following (from Google):

Differential Privacy: A system for sharing information about a dataset to reveal patterns of behavior, without revealing private information about individuals or whether they belong to the dataset.

K-Anonymity: A measure of anonymity within a dataset. If you have k=1000 anonymity, you can’t be distinguished from 999 other individuals in the dataset.

On-Device Processing: Computation is performed “locally” on a device (e.g., your phone or computer) without communicating with external servers.

Essentially, the Chrome browser itself will continue to track your online behavior, but the information that it sends to Google or other parties will be anonymized and categorized, rather than hyper specific (for example, you’re interested in baseball, rather than you visited a specific website related to the 1982 Milwaukee Brewers). These cohorts can still be used for targeting (and which targeting we’re actually talking about here, Google or Meta or all targeting, is something I’m not clear about).

What Apple and Safari Have Already Done

If Google’s elimination of third-party cookies sounds a bit like deja vu for Apple users, you’d be forgiven. This is something that Apple has been doing, in one form or another, since at least 2017.

Intelligent Tracking Prevention (ITP) blocks third-party cookies by default from Safari browsers. Of course, Safari makes up about 14% of all browsers. The inclusion of Chrome in this effort would likely be the final step to killing third-party cookies completely.

How This Impacts Meta Advertisers

The answer to this question is why you’re here, and I’d love to say I have a crystal clear directive. That may be partially because I’m not an expert on this topic, but there also seems to be quite a bit that we simply don’t know right now. This clarification is bound to come as data emerges from the initial 1% test.

What’s interesting is that almost all of the response I’ve read regarding the anticipated impact of this change was focused on targeting. I’m not sure if that’s a coincidence or if there will be less impact on attribution and optimization. Because I would assume that if third-party cookies were critical to attribution, that would be the bigger issue here.

Regardless, it would seem that the greatest risk is to anything that relies on third-party cookies. While the Meta pixel does use third-party cookies, it also uses first-party cookies by default (you can turn this off).

Whether first and third-party cookies provide something unique that the other can’t offer to the pixel is unclear. That would certainly add clarity to the impact of this roll-out.

The value of first-party data of all kinds going forward goes up. Which brings us here…

What You Should Do

As I said above, it’s not entirely clear how Chrome’s elimination of third-party cookies will impact Meta advertisers. But there are a couple of things that you should do, if you haven’t already.

1. Enable First-Party Cookies with the Meta Pixel.

Within Events Manager, go to Data Sources and then the Settings tab. There is a section for Cookie Usage.

Meta Pixel First-Party Cookies

From that screenshot above:

When first-party cookies are turned on, this provides additional data that helps Facebook deliver relevant ads to people who may be interested in your products or services.

First-party cookies should be on by default. If not, you can edit these settings to turn them on.

NOTE: There may be privacy considerations before turning on first-party cookies. Make sure to read Meta’s guidance on cookie usage here and here.

2. Connect the Conversions API.

We’ve been talking about connecting the Conversions API ever since about 2021 with Apple’s ATT tracking opt-out. It’s becoming more and more critical that you pass first-party data to Meta to be used for ads attribution and targeting. Otherwise, the accuracy gap will widen as third-party data is blocked.

You can pass server-side, first-party conversions data via the API using two different methods.

Conversions API for Web: Pass the same events that are sent from your pixel, but from a dedicated server. One popular solution is the API Gateway. I’ve set up the Gateway using Stape.

Conversions API for CRM: If conversions don’t happen online, another solution for providing a complete picture for attribution is sending the events from your CRM. A common scenario is when you have salespeople who call and close sales, which are marked via CRM tags.

It’s not clear whether these two steps are required to overcome the blockage of third-party cookies, whether they’re necessary, or whether they’ll even help. But until we know more, implementing both first-party cookies for your pixel and the Conversions API are good starts.

I don’t want to minimize the impact of the elimination of third-party cookies on Meta advertisers. At the same time, I’ve yet to see anything definitive that has me particularly concerned.

We’ve already seen the elimination of third-party cookies with Safari. You can turn on first-party cookies with the pixel and pass first-party data with the Conversions API.

Maybe changes will need to be made to the Conversions API and the data passed with the Meta pixel. Maybe publishers will be required to make adjustments to their websites. We’ll undoubtedly know more in the coming months.

But for now, those truly at risk are those who haven’t implemented first-party cookies with the pixel or the Conversions API.

Remaining Questions

As I’ve mentioned a few times, it’s still not clear to me how much these changes will impact Meta advertisers. It’s possible, if not likely, that there is an impact.

Here are some of the questions I’m left with, some which were mentioned throughout the post above…

1. What is the direct impact of eliminating third-party cookies to Meta advertising? The answer is surely found with clarity regarding how Meta is using third-party cookies now.

2. Does turning on first-party cookies for the Meta pixel solve for data that is otherwise lost from third-party cookies? Meta isn’t clear regarding how first vs. third-party cookies are used related to the pixel.

3. Does implementing the Conversions API solve for data that is otherwise lost due to browser cookies being blocked?

4. Will Meta need to make changes to the pixel and/or API related to these updates? Google has their own Attribution Reporting API. There’s also the matter of cohorts and topics for defining online behavior. Will these be used for Meta advertising, too?

5. Will the elimination of third-party cookies impact targeting, optimization, and attribution? Almost everything I’ve read has been focused on targeting. But maybe the reporters assumed that targeting is what matters most.


I dug through a long list of articles to assemble this blog post. Here’s a collection of resources that you could read to provide additional background.

Watch Video

I also recorded a video to walk through this. Watch it below…

Your Turn

If you’ve read any definitive details (from respected and dependable experts) that help clarify areas where I’m unsure, please provide a link to that information.

How are you preparing for the elimination of third-party cookies?

Let me know in the comments below!