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.
Latest posts

Combined technology gives marketers an enhanced view of the customer for improved planning, targeting and optimization NEW YORK, July 12, 2016/PR Newswire/ - Tapad, the leader in cross-device marketing technology and now a part of Experian, today announced a partnership with Conversion Logic, the martech industry's most accurate unified marketing attribution provider. Conversion Logic will incorporate unified cross-screen data from Tapad's Device Graph™ to identify related devices and media exposures to enhance reporting on the path to conversion. By connecting Conversion Logic's proprietary Ensemble Method, which combines numerous state-of-the-art machine learning algorithms, tuned for each customer use-case for the most accurate results, with Tapad's unified, cross-device technology, marketers will benefit from a highly scientific approach to assessing advertising effectiveness with full, comprehensive customer insights. Linking these technologies will increase marketers' real-time ability to optimize brands' marketing channel spend and creative at a more granular level. During the past six months, Tapad has rapidly grown its data business, doubling the number of companies integrating the Device Graph™ into their platforms and growing the annualized revenue run rate by 210%. Tapad's highly scalable, cross-device data has been confirmed by Nielsen to be very precise. Tapad augments platforms' and publishers' tech stacks with additional scale and relevancy, granting advertisers amplified targeting and analysis options. The growth of the Device GraphTM has allowed Tapad to provide a growing network that benefits all partners with more efficient, effective consumer engagement. "Combining highly accurate data from Tapad with our own user ID technology and understanding how devices may be related at an individual level provides additional visibility into the path to conversion," said Alison Lohse, COO and co-founder of Conversion Logic. "The more we know about the customer journey, the more effective, efficient and customized marketers can be with marketing efforts. With Tapad, we have achieved a unified customer view that helps us piece together the purchase journey while preserving proven accuracy." "Conversion Logic's Ensemble Method delivers singularly customized and precise results that are not just accurate, but actionable," said Dave Fall, COO of Tapad. "The combination of powerful technology and a user-friendly interface, plus Tapad's ability to only consider relevant and scalable components in the marketplace, creates a more concentrated and beneficial environment for both its partners and clients." Contact us today!

B2B marketers can now deliver the right message to the right user at the right time across devices and channels NEW YORK, NY–(Marketwired – Jun 1, 2016) – Madison Logic, one of the world's fastest growing companies dedicated to solving the digital needs of B2B marketers, is partnering with Tapad, the leading provider of unified and now a part of Experian, cross-screen marketing technology solutions. Now business-to-business (B2B) marketers can power targeted advertising and content syndication programs across all channels, including smartphones, computers and tablets. The increasing shift in content consumption across mobile devices makes cross-device identification and attribution a top priority for B2B marketers. The Madison Logic and Tapad partnership gives B2B marketers unprecedented reach and scale with the ability to run always-on, cross-device, account-based marketing programs targeting decision makers who are actively researching similar products and services. "Screens are everywhere and so is the B2B buyer," said Vin Turk, SVP of Audience Development for Madison Logic. "This partnership allows marketers to harness the power of Madison Logic's intent data and combine it with Tapad's cross-device solutions to connect with the most-likely-to-convert prospects with hyper-relevant content wherever and whenever they're doing their research." "Relevance is essential to the success of B2B marketers, particularly now, when breaking through the clutter is difficult," said Dave Fall, COO of Tapad. "This partnership with Madison Logic allows marketers to leverage their existing customers while identifying and reaching new audiences with messaging tailored to every device." For more information about Madison Logic's account-based marketing platform, please visit https://www.madisonlogic.com/account-based-marketing/. For more information about Tapad's cross-platform advertising solutions, please visit https://www.experian.com/marketing/consumer-sync. Contact us today!

NEW YORK, June 1, 2016 /PRNewswire/ — Are Traasdahl, CEO and founder of Tapad, the leader in cross-device marketing technology and now a part of Experian, has been named Founder of the Year by the Nordic Startup Awards. The Nordic Startup Awards' Founder of the Year Award recognizes an individual that has shown exceptional achievements in fundraising, customer growth, financial savvy, and/or leadership throughout the past year. The Nordic Startup Awards evaluates hundreds of players in the startup ecosystem, ranging from investors and founders, to developers and journalists in Denmark, Sweden, Iceland, Norway and Finland. Taking place in two stages, each country selects its nominees for consideration for the regional awards which were held in Iceland on May 31, 2016. Traasdahl is recognized for his continuous investment in Tapad as a whole, as well as his dedication to growing and developing Tapad since founding the company in 2010. He has led Tapad from startup through a steady period of growth resulting in an acquisition by the Telenor Group for $360 million in February 2016. "I am truly honored to be named Founder of the Year by the Nordic Startup Awards, among so many other remarkable leaders in the space," said Traasdahl. "That said, this has always been a team effort. We started Tapad with the goal of giving employees unprecedented growth opportunities while developing breakthrough solutions for our clients. This is a win for everyone at Tapad who has committed themselves to these principles over the past four-and-a-half years." Tapad is reinforcing its commitment to fostering entrepreneurship with the launch of their new Propeller Program. Through Propeller, Tapad will host five early-stage companies at Tapad's New York headquarters for a year to set them up for global expansion. In its inaugural year, the first participants will come from Traasdahl's native Norway. For more information on the Nordic Startup Awards, please visit: http://www.nordicstartupawards.com/. Contact us today!