In 2022, Google began changing the availability of the information available in User-Agent strings across their Chromium browsers. The change is to use the set of HTTP request header fields called Client Hints. Through this process, a server can request, and if approved by the client, receive information that would have been previously freely available in the User-Agent string. This change is likely to have an impact on publishers across the open web that may use User-Agent information today.
To explain what this change means, how it will impact the AdTech industry, and what you can do to prepare, we spoke with Nate West, our Director of Product.
What is the difference between User-Agents and Client Hints?
A User-Agent (UA) is a string, or line of text, that identifies information about a web server’s browser and operating system. For example, it can indicate if a device is on Safari on a Mac or Chrome on Windows.
Here is an example UA string from a Mac laptop running Chrome:

To limit the passive fingerprinting of users, Google is reducing components of the UA strings in their Chromium browsers and introducing Client Hints. When there is a trusted relationship between first-party domain owners and third-party servers, Client Hints can be used to share the same data.
This transition began in early 2022 with bigger expected changes beginning in February 2023. You can see in the above example, Chrome/109.0.0.0, where browser version information is already no longer available from the UA string on this desktop Chrome browser.
How can you use User-Agent device attributes today?
UA string information can be used for a variety of reasons. It is a component in web servers that has been available for decades. In the AdTech space, it can be used in various ad targeting use cases. It can be used by publishers to better understand their audience. The shift to limit access and information shared is to prevent nefarious usage of the data.
What are the benefits of Client Hints?
By using Client Hints, a domain owner, or publisher, can manage access to data activity that occurs on their web properties. Having that control may be advantageous. The format of the information shared is also cleaner than parsing a string from User-Agents. Although, given that Client Hints are not the norm across all browsers, a long-term solution may be needed to manage UA strings and Client Hints.
An advantage of capturing and sharing Client Hint information is to be prepared and understand if there is any impact to your systems and processes. This will help with the currently planned transition by Google, but also should the full UA string become further restricted.
Who will be impacted by this change?
Publishers across the open web should lean in to understand this change and any potential impact to them. The programmatic ecosystem supporting real-time bidding (RTB) needs to continue pushing for adoption of OpenRTB 2.6, which supports the passing of client hint information in place of data from UA strings.
What is Google’s timeline for implementing Client Hints?

Do businesses have to implement Client Hints? What happens if they don’t?
Not capturing and sharing with trusted partners can impact capabilities in place today. Given Chromium browsers account for a sizable portion of web traffic, the impact will vary for each publisher and tech company in the ecosystem. I would assess how UA strings are in use today, where you may have security concerns or not, and look to get more information on how to maintain data sharing with trusted partners.
We can help you adopt Client Hints
Reach out to our Customer Success team at tapadcustomersuccess@experian.com to explore the best options to handle the User-Agent changes and implement Client Hints. As leaders in the AdTech space, we’re here to help you successfully make this transition. Together we can review the options available to put you and your team on the best path forward.
About our expert

Nate West, Director of Product
Nate West joined Experian in 2022 as the Director of Product for our identity graph. Nate focuses on making sure our partners maintain and grow identity resolution solutions today in an ever-changing future state. He has over a decade of experience working for media organizations and AdTech platforms.
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Industry leaders recently gathered at the influential Beet Retreat 2023 conference held in Santa Monica, sharing forward-looking perspectives on the future of advertising. This renowned event known for its diverse mix of leaders from TV, agencies, advertising, and technology sectors, was enriched by insights from Experian’s very own Chris Feo, SVP of Sales & Partnerships, and Kimberly Gilberti, Chief Product Officer. Both Feo and Gilberti brought their expertise and perspectives for harnessing the potential of high-growth connected TV (CTV) advertising. The era of connected everything at Beet Retreat 2023 In the “Era of Connected Everything,” panel, Feo dived into the concept of a ‘connected everything’ world. He emphasized the importance of balancing consumer and privacy expectations with the increasing integration of AI and machine learning. “As decisioning evolves, creative tech and data derived from creative scale will play a bigger role.”chris feo, svp, sales & partnerships Feo further discussed the potential of creative technology, particularly in how AI and machine learning could revolutionize content personalization. He cited examples where the same creative content is used indiscriminately across diverse demographics, suggesting a future where creative content adapts and performs well for a variety of audience identities. Experian's balanced approach at Beet Retreat 2023 During a fireside chat, Gilberti shared her vision on the transformative role of television in the advertising technology landscape. “Connecting exposure to business outcomes is the holy grail of measuring CTV and effectiveness.”kimberly gilberti, chief product officer Her insights reflected the growing interplay between digital and traditional TV advertising, and the opportunities arising from this convergence. Gilberti emphasized the critical role of data analytics in enabling advertisers to tailor content more effectively to diverse TV audiences. She envisioned a future where the integration of digital strategies and traditional TV advertising create a more cohesive and impactful AdTech approach. Future focus: Diversification and partnerships Both Feo and Gilberti underscored the need for advertisers to diversify their partnerships. By working with a variety of partners, you can mitigate risks and foster innovation, ensuring you are not overly dependent on a single channel or approach. Navigate what’s next with Experian Experian's contributions at Beat Retreat 2023 underscore our pivotal role in the AdTech industry. With a unique balance of offline and online data expertise, we are not just adapting to changes but leading the way in innovation and strategy. Our insights and approaches, as highlighted by Feo and Gilberti, demonstrate our commitment to guiding the industry through its rapid evolution, making our role indispensable in the future of advertising technology. At Experian, we’re your partner in data-driven marketing and can help make your interactions more meaningful. To learn more, connect with a member of our team today. Connect with us Latest posts

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In this article… What is a walled garden? Integrated marketing is more important than ever Perspectives on walled gardens from Cannes Lions 2023 Walled gardens aren’t going away in the near future The fuure of walled gardens Digital marketers face an ongoing challenge in the form of "walled gardens," closed online ecosystems where it is difficult to access user data. As we get ready for 2024, it's more important than ever for marketers to evaluate the current challenges and opportunities surrounding walled gardens and to take stock of the impact of walled gardens in marketing as an industry. What is a walled garden? A walled garden is a closed online ecosystem controlled entirely by one tech company. Advertising on these ecosystems is fairly locked down, as major tech companies with walled gardens tend to tightly control access to the user data, content, and advertising that appears within the ecosystems. Some examples of walled garden ecosystems include Google, Facebook, Amazon, and Apple. These walled gardens have particular advantages, like access to massive user bases and precise targeting within the individual ecosystems. It can also be difficult to reach said audiences outside of the ecosystems, reducing the amount of control you have over your advertising strategies. Learn more about walled gardens. Learn the differences between walled gardens and hedged gardens. Integrated marketing is more important than ever Today, it's become more crucial to connect with consumers over multiple touchpoints, which can be done from tech like connected TV (CTV) to websites, mobile devices, and even shopping in a physical store. However, as integrated marketing gains utility, many platforms with walled garden ecosystems have increased, making a truly integrated and personalized marketing strategy more difficult in many situations. As a result, many marketers have realized the value of a more streamlined marketing approach, emphasizing the importance of fully integrated advertising strategies. Though there are surely marketing advantages to gain from walled garden ecosystems, especially in audience size, the challenges they pose will require you to innovate and find more creative ways to engage with your audience from platform to platform. Perspectives on walled gardens from Cannes Lions 2023 Offering a poignant view of industry trends and ideas, the Cannes Lions International Festival of Creativity of 2023 had much to say about the significance of walled gardens in the marketing world. Let's look at two key takeaways from this year's festival. Retail media In recent years, many retail companies have started selling ad space within their own walled garden shopping platforms, dubbed "retail media." Platforms like Amazon and Walmart have developed their own particular advertising ecosystems where they sell ads to marketers within the shopping environment itself. Navigating the sell-side of retail media’s walled gardens While retail media offers marketers unique opportunities, it's not without its challenges. For one, ad space in these environments is limited, so the competition can be difficult on the sell-side, leading to higher ad costs. Additionally, this shift in dynamic also forces marketers to change how they prioritize their marketing channels, looking closer at the results of their efforts rather than focusing on particular channels within the platforms themselves. Opportunities in the buy-side of retail media’s walled gardens Brands on the buy-side see various benefits from advertising within retail media channels and walled gardens. By browsing in an online shopping environment, the users in these ecosystems are likely high-intent shoppers, people who are further down the sales funnel and who are ready to make a purchase soon. Shoppers can also be precisely targeted within these environments, as marketers are given the ability to access very specific audience segments based on details like shopping behavior, preferences, and even purchase history. Omnichannel marketing To more effectively engage audiences even among an abundance of walled garden ecosystems, speakers at the 2023 Cannes Lions Festival discussed the importance of omnichannel marketing. By emphasizing strategies that reach the consumer through multiple touchpoints, marketers can deliver a unified brand experience across channels. This allows marketers to focus more on results than specific advertising channels, including walled garden platforms. Walled gardens aren’t going away in the near future Though various challenges are associated with walled gardens in advertising, they aren't going anywhere. So, what's the current state of these environments throughout the industry? Efforts are being made to break down walled gardens in tech In a handful of countries, regulatory actions have been put forward to address how dominant many major tech companies are in their respective markets. One major example of this is Meta and Google's entanglements in Canada. Currently, neither company can display news on their websites in the Canadian market. This decision was reached to give Canadian news agencies more control over their advertising revenue since, previously, the tech giants received more views and, therefore, gained the ad revenue. Though relatively small, this does indicate a certain shift in dynamic. Why companies are resisting Despite their challenges, walled gardens in 2023 persisted, mainly because they are particularly adept at generating revenue for the tech companies that control them. In 2022, 78 percent of global digital advertising revenue came from these closed ecosystems, and projections expect that figure to rise to 83 percent by 2027. From the viewpoint of a company that operates in a walled garden, the idea of releasing their control over their environment represents losing out on a stream of vast revenue, making letting go of a walled garden ecosystem an unattractive prospect. The future of walled gardens As time progresses, what can digital marketers like you expect from walled garden ecosystems in the near future? A cookieless future A huge element to consider is the transition to a cookieless future. Many major browsers have begun phasing out the use of third-party cookies. 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Navigating the evolving landscape of walled gardens in 2024 As we begin 2024, you will continue facing opportunities and challenges regarding walled gardens. The 2023 Cannes Lions International Festival of Creativity re-emphasized how important it is for marketers to stress omnichannel marketing within walled garden environments and become well acquainted with identity resolution solutions as we move into a cookie-less future. All of this requires you to become comfortable with walled gardens being here to stay and innovate to navigate an evolving and developing landscape. We’re here to help you navigate the evolving landscape of walled gardens in 2024. Contact us today. Get in touch Latest posts