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

Tapad's, part of Experian, SVP of Identity shows us how marketers might communicate seamlessly through emerging channels like voice, the smart home, and, yes, podcasts.In his relatively new role as senior vice president of identity at Tapad, a part of Experian, Ajit Thupil keeps a close eye on the evolution of marketing as it becomes more intent on using data and identity technology to track ROI. Here he sits with Chris Wood at Tapad’s New York offices to discuss the future of identity. (To capture the inventive atmosphere at this location, the room they chatted in was named after Leonardo da Vinci.) For Thupil, it all comes back to the customer, whether it’s a brand client or a consumer. Brands want measurability and customers demand a seamless experience across the many devices they use in a day. While consumers are understandably reticent about giving up personally identifiable information (PII), current identity solutions use anonymous data profiles to connect the dots at the individual or household level. Given the frequency that users switch devices, along with their tendency to share bigger screens like TVs, there’s no dearth of challenges for this “head of problem solving” to solve. Contact us today!

Joint solution will enhance accuracy and reach across North America, EMEA and APAC NEW YORK, April 17, 2019 /PRNewswire/ — Tapad, a global marketing technology company and leader in digital identity resolution solutions, today announced a new joint capability with Arm®Treasure DataTM , a leader in enterprise customer data management. The partnership combines The Tapad GraphTM technology with Arm Treasure Data's robust enterprise Customer Data Platform (CDP), enabling advertisers in the Arm Treasure Data marketplace to access Tapad's datasets. With the integration of Tapad's Graph and Arm Treasure Data's existing first party data, marketers will be able to deliver scalable, cross-device messaging with precision. In addition, marketers can benefit from anonymous customer journey analysis, audience expansion and online and offline attribution. Arm Treasure Data's APAC market customers will have access to expanded audience reach by leveraging Tapad's global, proprietary datasets. While Tapad will be able to extend its presence into the APAC region, tapping into Arm Treasure Data's existing footprint. "Combining Tapad's Graph with Arm Treasure Data's CDP will enable our customers to make holistic, data-driven decisions that increase ROI," said Chris Feo, SVP of Global Data Licensing and Strategic Partnerships at Tapad. "In combining these two solutions, we can now offer advertisers the value of both technologies to optimize their marketing initiatives and create seamless experiences across multiple devices and channels." "The Tapad GraphTM is a trusted and established platform with a history of innovation," said Stephen Lee, Senior Director, Business Development, Arm Treasure Data. "Integrating Tapad's technology into the Arm Treasure Data CDP will allow for streamlined experiences across markets, achieving global scalable reach." For more information about The Tapad GraphTM, or to request a demo, visit our identity page. Contact us today! About Tapad Tapad, Inc. is a global marketing technology company and leader in digital identity resolution solutions. The Tapad GraphTM, and related solutions, provide a privacy-safe approach to connecting device identifiers to brand and marketer data, thereby allowing for enhanced measurement, attribution, reach and ROI of marketing campaigns. The Tapad GraphTM enables marketers around the world to maximize campaign effectiveness and drive business results. Tapad is recognized across the industry for its innovation, growth and workplace culture, and has earned numerous awards, including the TMCnet Tech Culture Award. Based in New York, Tapad also has offices in Chicago, London, Oslo, Singapore and Tokyo, and is a wholly owned subsidiary of Telenor Group. About Treasure Data Arm Treasure Data enterprise Customer Data Platform (CDP) unifies data from multiple sources – online, offline, IoT and device generated data – and empowers enterprises to disrupt their markets with superior customer experiences. Our customers are creating transformational customer relationships by connecting the data dots with our CDP. Arm Treasure Data is fully owned by Arm Holdings and has a global customer base of over 300 enterprises including Fortune 500 and Global 2000 companies. Our clients manage over 130 trillion records, resulting in more predictable and profitable business results.

Leading global marketing technology company, Tapad, a part of Experian, adopts The Trade Desk’s streamlined cookie ID into its identity resolution solutions to increase global cookie coverage across the internet April 03, 2019 09:00 AM Eastern Daylight Time LOS ANGELES & NEW YORK–(BUSINESS WIRE)–Global marketing technology company, Tapad, a part of Experian, has partnered with The Trade Desk to onboard The Trade Desk’s unified ID solution into its digital identity driven solutions. The Trade Desk’s unified ID solution is free for all parties spanning the digital advertising supply chain, including SSPs, DSPs, DMPs and data providers. With leading players onboarding the unified ID solution, such as Tapad, streamlined cookie syncs make ad viewing experiences better for consumers, increase match rates for all parties, and expand cookie coverage on a global-scale. Adoption of The Trade Desk’s global cookie footprint enables Tapad customers to benefit from greater precision and potentially higher performing digital marketing campaigns. “Digital identity resolution is key to improving digital marketing campaigns. Supporting The Trade Desk’s unified ID solution, in conjunction with our cross-device and identity resolution offerings, helps us and the entire open ecosystem,” said Chris Feo, SVP of Global Data Licensing and Strategic Partnerships at Tapad. “It simplifies cookie syncing, and increases match rates among our partners; enabling our customers to improve marketing campaign performance.” “Identity is critical in the ecosystem and as a long-standing leader in the space, Tapad has shown a strong commitment to building digital identity resolution solutions that help marketers launch more effective campaigns on a global scale,” said Ed Chater, VP of Data Partnerships, The Trade Desk. “We are thrilled for their participation and look forward to solving the digital identity narrative across the industry through this partnership. The continued widespread adoption of the unified ID solution validates our collective mission to improve the effectiveness of digital advertising.” About Tapad Tapad, Inc. is a global marketing technology company and leader in digital identity resolution solutions. The Tapad Graph™, and related solutions, provide a privacy-safe approach to connecting device identifiers to brand and marketer data, thereby allowing for enhanced measurement, attribution, reach and ROI of marketing campaigns. The Tapad Graph™ enables marketers around the world to maximize campaign effectiveness and drive business results. Tapad is recognized across the industry for its innovation, growth and workplace culture, and has earned numerous awards, including the TMCnet Tech Culture Award. Based in New York, Tapad also has offices in Chicago, London, Oslo, Singapore and Tokyo, and is a wholly owned subsidiary of Telenor. About The Trade Desk, Inc. The Trade Desk™ is a technology company that empowers buyers of advertising. Through its self-service, cloud-based platform, ad buyers can create, manage, and optimize more expressive data-driven digital advertising campaigns across ad formats, including display, video, audio, native and, social, on a multitude of devices, such as computers, mobile devices, and connected TV. Integrations with major data, inventory, and publisher partners ensure maximum reach and decisioning capabilities, and enterprise APIs enable custom development on top of the platform. Headquartered in Ventura, CA, The Trade Desk has offices across North America, Europe, and Asia Pacific. To learn more, visit thetradedesk.com or follow us on Facebook, Twitter, and LinkedIn. Contact us today!