Cookieless World

First-Party vs. Third-Party Cookies: What’s the Difference?

Illustrating the differences between first-party vs. third-party cookies

Last Updated on: 26th May 2024, 07:38 pm

Cookies play an essential role in the modern internet. These small pieces of data stored in your web browser can do everything from saving login details to enhancing website performance to helping marketers show users products that they will love. However, not all cookies are made equal, and there are significant differences between first-party and third-party cookies. 

This article will walk you through how cookies work and cover the main differences between first and third-party cookies. In this article, you will learn:

  • What cookies are and how they work.
  • The differences between first-party and third-party cookies.
  • Why third-party cookies are being depreciated by many web browsers due to privacy concerns. 
  • How you can use Deep Learning to navigate the cookieless future. 

Table of Contents:

What are cookies, and how many types are there? 

Cookies are essentially small pieces of data, specifically text files, that are created by websites and stored within your web browser. These files can contain information about your browsing history on that website or provide other functions. Whenever you visit a website with a cookie, your browser sends the cookie back to that website’s server, allowing it to recognize you and remember details about your previous visits, such as settings, carts, or browsing history. 

It is important to keep in mind that while people often talk about first-party and third-party cookies as though they are different things, the technology is exactly the same. The difference lies in how they are used: 

  • First-party cookies: are created and stored by the website you are directly interacting with. They are used to enhance your browsing experience by remembering your preferences and settings specific to that website.
  • Second-party cookies: are technically a type of first-party cookie, however, you will sometimes see the term used to describe cookies that are created by a trusted partner or an entity that has a direct relationship with the website you are visiting. For example, when you book a flight, your airline might offer your first-party cookies and other data to a car rental company for targeted ads, classifying it as second-party.
  • Third-party cookies: are created and stored by websites other than the one you are currently visiting. They are often used by advertisers, analytics providers, or social media platforms to track your browsing behavior across multiple websites and deliver targeted advertisements or gather analytics data.
    Guide to a Multiple Retargeting Strategy [REPORT]
    This guide debunks the most popular myths regarding the multiple retargeting strategy and provides tips and best practices on how to get the most out of advertising efforts.

What are first-party cookies?

First-party cookies are created by the website you are directly interacting with. They fulfill a variety of purposes to enhance your browsing experience and provide personalized services. First-party cookies remember your preferences, such as language settings, font size, and items in your shopping cart, enabling improved navigation and customization. 

They also help maintain your login status, ensuring you stay authenticated during your visit to the website. Additionally, first-party cookies contribute to website analytics, allowing website owners to understand user behavior, improve their services, and deliver relevant content. Overall, first-party cookies play a vital role in delivering a smoother, personalized, and user-friendly browsing experience on a specific website and have few, if any, privacy concerns. 

What are third-party cookies? 

Third-party cookies are created and stored by websites other than the one you are currently visiting and are primarily used for tracking user behavior across multiple websites. These cookies enable advertisers, analytics providers, and social media platforms to collect data about your browsing activities, interests, and preferences.

With this information, companies can deliver targeted advertisements, create user profiles, and personalize content across various websites. Third-party cookies allow for more extensive tracking and data sharing, enabling advertisers to reach specific audiences and measure the effectiveness of their campaigns. 

What are the privacy concerns around third-party cookies? 

The problem? Third-party cookies have raised significant privacy concerns due to their ability to track users across multiple websites. When collected and put together, these cookies can provide extensive information, which can be used to create a detailed user profile without their informed consent. 

This concern has led to a rethink of how third-party cookies operate, and Google is retiring third-party tracking cookies from its Chrome browser in early 2025. Despite these concerns, third-party cookies are simply a piece of technology which is most often used for legitimate marketing purposes in a way that respects a user’s privacy. However, like all technology, in the wrong hands, third-party cookies can be exploited in ways that compromise user privacy or for other malicious purposes. 

Third-party cookies vs. first-party cookies

So, now that we’ve covered what they are, let’s look at the differences between third-party cookies vs. first-party cookies:

  • First-party cookies are very limited in scope and link your browser to the webpage you use and share basic information only with that webpage owner, they don’t track you around the web. There is little controversy surrounding their use.
  • Third-party cookies are not tied to a single website. They are typically used by marketers and social media networks to track users, build advertising profiles, and deliver relevant ads. There are significant privacy concerns surrounding their use. 

Key differences between first and third-party cookies:

Table illustrating differences between first vs. third-party cookies

First and third-party cookies in the context of the cookieless future

An important thing to note here is that an increasing number of browsers have already decided to eliminate third-party cookies or have plans to do so in the near future. This won’t affect first-party cookies at all, but it will mean that marketers need to find alternatives to third-party tracking cookies in the cookieless future

Retargeting is in a particularly tricky position. Third-party cookies were a powerful tool for good-faith advertisements to reach users. Unfortunately, this cuts both ways, and bad actors stoked privacy concerns and made the depreciation of third-party cookies a necessary step to make the internet a safer place. This is cold comfort for retargeters, whose job is now much more difficult. It is harder to reach users and harder to show them content that they actually want to see and engage with. 

At RTB House, we’ve been working to implement Google Chrome’s solution to the problem: the Protected Audience API, previously known as FLEDGE API. This API moves all bidding to the device level and enables marketers’ DSPs to purchase impressions without access to an internet user’s personal information. This solution is designed to prevent third parties from tracking individual users’ browsing behavior across sites while maintaining the utility of third-party tracking cookies. 

Our early experience co-authoring and providing feedback on the Protected Audience API is helping to improve our Deep Learning model, which will give RTB House and our customers a significant advantage once third-party tracking cookies are finally retired. 

If you want to learn more about the cookieless world, check out this section. 

Whether you’re using cookies or going cookie-free, RTB House can help you

One of the most important takeaways here is that while there are many solutions which allow personalized marketing, not all are privacy-friendly and future-proof. This makes it essential to partner with a vendor that has its eye on long-term sustainable solutions.  

At RTB House, we rely on our (not so) secret weapon: Deep Learning algorithms. Deep Learning passes data through layers and uses a neural net inspired by the structure of the human brain to draw increasingly complicated conclusions. This allows the algorithm to learn as more data is fed into it, and it is able to handle complicated, diverse datasets. 

We use Deep Learning in every single one of our advertising solutions. This has positioned RTB House to thrive in the cookieless future, and we can help your company do the same. 

To talk more about privacy-friendly retargeting and how you can adopt a data-driven marketing approach, reach out to our team today.

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