Google Chrome will join Firefox and Safari in phasing out third-party cookies, eventually reaching 100% of users globally by Q3 in 2024. The browser has already started making headway, with third-party cookie access restricted for a randomly selected 1% of users as of 4 January 2024.

Based on data from Statista, this will apply to over 3.22 billion internet users. Some third-party services can participate in depreciation trials by applying for temporary cookie access, but eligibility is extremely limited.

Google will only consider this extension for services with confirmed functional breakage, not data collection issues. Otherwise, the randomly selected users will receive “Tracking Protection”, which inhibits websites from accessing third-party cookies that track users across the web.

If Chrome detects issues while browsing (like if you refresh a page multiple times), a prompt from the eye icon on the right side of your address bar will appear. You will then be asked if you’d like to re-enable third-party cookies for the site temporarily.

This could lead to using first-party cookies to provide a better user experience by collecting data about a user’s interaction with a website, enabling them to tailor content to that user. While they contain the same information and can perform the same functions as third-party cookies, it’s vital to understand how they’re different.

First-party vs. third-party cookies

The difference between first-party and third-party cookies lies in how they are created and used. This usually depends on the context. First-party cookies are typically generated by the host domain and placed on the user’s device by the site they visit.

These cookies can improve the user experience on that particular site, such as by remembering login details, language preferences, or shopping cart contents. Third-party cookies are typically generated and placed on the user’s device by a site other than the one the user is visiting.

For instance, if you visit website A but the cookie is set by website B (a third-party), that’s a third-party cookie. As you continue browsing, these cookies collect data about your activities, which is then sent back to website B (third-party).

Over time, these cookies help create a profile of your interests based on the websites you visit and your online actions. Third-party core functions include tracking a user’s online behaviour across different websites.

This tracking enables data collection on a user’s browsing habits, preferences, and interests. Advertisers use the data collected by these cookies to serve targeted ads to users. For example, if you browse various online stores for shoes, you might later see shoe ads on different websites.

What are the pros and cons of first-party cookies?

First-party cookies are great for creating the best user experience for your website visitors, but they also have some downsides. Discover their benefits and drawbacks below.


  • Users know when they visit a site that data about their visit isn’t leaked elsewhere, alleviating any privacy concerns.
  • As first-party cookies track user behaviour only on the visited site, the host domain has complete control and ownership of the collected data.
  • First-party cookies optimise website speed and allow visitors a personalised and much smoother website experience by remembering user preferences and login information.
  • While users can delete all cookie types, third-party browsers or software do not automatically block first-party cookies. This means their adoption rate among internet users is wide.
  • Applying first-party cookies means users will see your brand instead of another site


  • Website owners can’t see what a user does once they leave their site.
  • It’s impossible to track individual users on the same computer, unless they have their login credentials.
  • Unable to create omnichannel marketing strategies as advertisers cannot leverage first-party cookies to track customers across channels and devices.

What are the pros and cons of third-party cookies?

The main issue for consumers with third-party cookies is they feel they invade their privacy.

However, they are not inherently bad — let’s look at their pros and cons.


  • Allows advertisers to tailor ads based on browsing history, interest, wider online behaviour, and user demographics.
  • Allowing websites to remember log information, preferences, and shopping cart content improves the overall user experience.
  • Understanding how site owners’ audiences interact with their sites can help them optimise their offerings.


  • Tracking activities across multiple sites without explicit consent, leads to personal data security and privacy concerns. In addition, this data is owned and processed by third-parties. With increasing data protection regulations, third-party cookies are becoming more complex and legally challenging.
  • Cookies can be used in the same way to understand and collect data for tailored experiences, compromise personal information, or deliver malware.
  • Users can block or delete cookies, and some browsers are now set to block third-party cookies by default. This can lead to inaccurate tracking and data collection — thus invalidating marketing and advertising insight.

Why is Google restricting third-party cookies?

The main criticism aimed at third-party cookies is the feeling of consumers that their privacy is being invaded. But what are the reasons behind Google’s grand plan to block third-party cookies in Chrome?

Privacy concerns

In recent years, public concern about privacy and data protection has grown. Third-party cookies are often seen as intrusive because they can track users’ browsing activities across websites without explicit consent.

By limiting these cookies, Google is responding to these privacy concerns and aligning with global trends towards more stringent data privacy regulations, like the EU’s General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA).

Shift to first-party data

Google is likely encouraging a shift towards first-party data collection, where data is collected directly by the website a user visits. This approach is generally seen as more privacy-friendly and reliable.

How does this impact marketers?

The biggest effect of eliminating third-party cookies for marketers is the ability to build audiences, but first-party data offers a beacon of hope for them to deliver more personalised campaigns.

Let’s look at this and other ways it will impact marketing strategies.

Improve accuracy and relevancy of machine learning models

For AI systems like Bard, having access to robust first-party data can enhance the accuracy and relevance of the AI’s outputs without compromising user privacy.

Targeted advertising and personalisation

It’s no secret that many advertisers rely on these cookies to track users across the web and serve them targeted ads. They will now have to find new methods to reach their audience online.

Personalised ads, in particular, will be hit heavily, as brands won’t have as many insights into consumers’ browsing and purchasing history.


The adtech industry and data management platforms rely on third-party cookies and trackers for targeting and boosting their business.

Measurement and attribution

Marketers will also need to find new ways to measure the success of their campaigns, as A/B testing will become a challenging task. Without third-party cookies, a visitor to a website is seen as new every time.

This means multiple A/B test variants will not be visible, resulting in the likelihood of unreliable attribution of conversion to each variation. However, first-party cookies will still be effective for A/B testing.

Other attribution techniques that will be affected include:

  • Loss of cross-site tracking
  • Cross-device tracking (mobile to desktop)
  • Some attribution models rely on 3rd party cookies to measure touchpoints.

How do we prepare for this?

Marketers can navigate the phasing out of third-party cookies by implementing a first-party data strategy and ensuring they have the tools to implement it.

This will allow you to collect and use customer data in a more privacy-conscious and user-friendly way. Adopting some or all of the following methods will mean you’re more than prepared when third-party cookies disappear.

Rethink your analytics

As with any major changes to user insight, it creates an opportunity to re-imagine how you use your analytics and targeting.

For example, move away from thinking of your users as individuals but as a cohort of people with similar interests.

Develop a proper consent setup

Google has updated the consent mode API, including parameters for user data consent and personalised advertising.

Build on first-party data

This is the lowest-hanging fruit for site owners. It involves collecting email addresses, contact info, demographics, and sales history data directly from your users.

This data can be collected through form fills, customer surveys, or site interaction analytics.

Use Google’s Privacy Sandbox APIs

For example, the Protected Audience API enables browsers to conduct on-device auctions, allowing them to choose relevant ads from sites previously visited by users without tracking their browsing behaviour across different sites.

Because this is available in GA4, analytics will work without third-party cookie enablement and use machine learning to gather analytics and understand consumer journeys.

Also, consider auditing your vendors and setting up the browser to block third-party cookies to test for breakages.


Third-party cookies have long been the foundation of the online ecosystem, but users are becoming more sensitive to the unauthorised collection and use of their personal data. Trackers have also become increasingly inefficient and ineffective for digital advertisers when it comes to targeting users and tracking performance.

Google’s announcement is another step in preparing us for a longer-term view of customers. This means site owners must adapt by ethically creating rich databases of first-party data.

By replacing third-party cookies with less intrusive methods, you can quickly build trust with your target audience and future-proof your customer acquisition strategy.