That was the final word in Q3 2024. For advertisers, it wasn’t clear what would come next, as cookies had been a fixed part of the advertising landscape for a long time.

Now that they’re gone, a lot has to change. What has happened so far, what cookies actually are, and how things will continue—we’ve summarized it all here. Let’s dive in.

What Has Happened So Far

Before we look at what will be relevant for advertisers from 2024 onward, let’s take a look at developments from 2020 up until now.

Due to privacy concerns, browsers like Safari and Firefox had already phased out third-party cookies, while Google, as the market leader in browsers, opted for a gradual transition. The change can be outlined as follows:

• 2020: Google announced plans to phase out third-party cookies by 2022. However, uncertainty in the advertising industry was high, and initial alternatives were discussed.

• 2021: Optimism grew as Google worked on alternatives through the Privacy Sandbox. Early details on new tracking methods emerged.

• 2022: The phase-out was delayed due to the lack of a privacy-compliant successor technology. Google extended the use of third-party cookies until 2024.

• 2023: Alternatives such as first-party data, semantic, and contextual targeting gained traction, but many companies were still unprepared.

• 2024: Google began gradually phasing out third-party cookies in Chrome. During a test phase, cookies were deactivated for 1% of users before being completely phased out in Q3 2024.

The real-world implementation will show whether Google’s alternatives will fundamentally reshape the advertising market or bring new challenges.

What Exactly Are Third-Party Cookies Again?

They were phased out due to privacy concerns—but what exactly are cookies?

Cookies are small data packets stored on a user’s device that contain information about their interactions with websites. They serve various functions, including session management, content personalization, and behavioral analysis. There are two main types of cookies: first-party cookies and third-party cookies.

• First-party cookies are set by the website a user visits and mainly improve the user experience. They help save login details, manage shopping carts, and personalize content based on user interests. Since they are only used within a website’s own domain, they are considered less invasive and are essential for many websites.

• Third-party cookies, on the other hand, are placed by external providers and enable cross-site tracking. They are embedded via content such as YouTube videos, social media widgets, or ads, allowing brands and advertisers to create detailed user profiles for targeted advertising. However, they pose privacy risks as they collect personal data and can sometimes be exploited for malicious purposes. While they are often used for retargeting and personalized ads, they are generally not necessary for a website’s core functionality.

Why Are Third-Party Cookies Problematic?

We’ve mentioned privacy concerns multiple times—but what exactly does that mean?

Third-party cookies were initially introduced to facilitate online shopping and other web functionalities, but their potential for misuse and privacy violations soon became evident. They allow marketers to track users across different websites without their explicit consent, leading to a loss of trust and a lack of control over personal data. Cybercriminals also exploit them for identity theft and the extraction of sensitive information.

As internet users increasingly prioritize privacy, many rely on ad blockers, presenting challenges for digital advertising. At the same time, privacy laws like the GDPR and TTDSG have imposed stricter regulations on cookie usage. Websites must now obtain explicit user consent, inform users about tracking technologies, and document data processing. Violations can result in hefty fines.

In response to these developments, leading browsers have started phasing out third-party cookies, paving the way for new, privacy-friendly marketing and advertising technologies.

For more details, check out: Piwik Pro - The End of Third-Party Cookies.

What’s Next?

Good question! Since we use different browsers on the internet, there’s no one-size-fits-all answer. Piwik Pro has compiled a list of what Google’s Chrome browser is planning.

As part of the Privacy Sandbox project, Google will remove support for third-party cookies in Chrome. The goal is to enable advertising functions through new technologies—without tracking users across websites.

The Privacy Sandbox is developing and testing various APIs, including:

• Topics: Determines user interests based on browsing history without detailed tracking.

• Protected Audience: Enables targeted advertising directly within the browser without sharing personal data.

• Attribution Reporting: Measures ad conversions without tracking individual users.

• Private Aggregation: Creates aggregated reports on large user groups.

• Shared Storage: Stores cross-site data securely.

• Fenced Frames: Embeds content without sharing data between websites.

However, the Privacy Sandbox remains controversial. Critics argue that it only works in Chrome and prevents advertisers from storing their own user identifiers. According to the IAB Tech Lab, smaller media companies and brands could be disadvantaged. The proposals are still in development, and other alternatives to the Privacy Sandbox are being explored for the post-third-party-cookie era.

And What About Other Browsers?

Other browsers have reacted as well—some even earlier than Google:

• Safari (Apple) blocks third-party cookies with Intelligent Tracking Prevention (ITP) and requires explicit consent for app tracking via App Tracking Transparency (ATT) on iOS.

• Firefox offers Enhanced Tracking Protection, which allows users to customize tracker blocking.

• Brave has prioritized privacy from the start, blocking third-party cookies by default and incorporating numerous security features.

As we can see, the shift away from third-party cookies began well before Google’s move.

What Should Advertisers Do Now?

The fact is that the advertising landscape has changed—there is now less data available to create personalized customer experiences.

The cookieless future describes a world where third-party cookies are no longer used for marketing and user tracking. This presents challenges for digital marketing but also opens up opportunities for innovation. Companies already relying on first-party cookies are largely unaffected, as these can still be used for web analytics, product analysis, marketing tools, and onsite personalization. Retargeting on mobile devices also remains possible via mobile IDs.

To prepare for the new privacy landscape, companies should focus on first-party data—data collected through direct customer interactions, such as personal details, purchase history, or social media activities. Additionally, zero-party data is becoming increasingly valuable, as it is shared voluntarily by users through opt-ins, reviews, or personal preferences. Since this type of data collection is based on transparency and consent, it strengthens customer trust while providing reliable insights for marketing strategies.

Summary

The phase-out of third-party cookies marks a profound shift in digital marketing. While it initially poses challenges for tracking, targeting, and personalization, it also creates opportunities for privacy-friendly and sustainable strategies. Companies that embrace first-party and zero-party data early can gain a competitive advantage and build stronger customer relationships.

Technologies like the Privacy Sandbox and alternative tracking methods demonstrate that digital marketing can thrive without third-party cookies. The key now is to adapt flexibly and develop innovative, transparent solutions for the future.

Want to read more blog articles? Check out: F7 Blog.