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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Sixty-Nine Percent Organic Sales Growth Spurred by Expanded Business and Continued Investment in The Tapad Graph™ NEW YORK, May 7, 2019 /PRNewswire/ — Tapad, a part of Experian, a global leader in digital identity resolution, today announced a record start to the year, following its highest earning year in the company's history. Since January, Tapad has experienced a 69 percent organic increase in global revenue; with strategic investments in talent, continued high retention rates, and an expanded range of clients across global markets. Globally, Tapad increased its client base across multiple categories and verticals, catering to agencies, brands, telecoms, and data providers. The Tapad Graph™'s varied use cases and differentiated global scale have been instrumental to the company's overall success to-date. With an ongoing investment in product, and expected feature releases slated for 2019, the company anticipates these accomplishments to continue. "Since the inception of our business, Tapad has heavily focused on enabling marketers to boost the performance of their campaigns with the help of our advanced digital identity resolution technologies," said Sigvart Voss Eriksen, CEO at Tapad. "While we continue to grow, creating privacy-safe solutions that solve marketers evolving needs remains integral to our evolution. As pioneers in cross-device, we're constantly innovating and pushing ourselves to be at the forefront of industry change. Our leadership in the space is recognized across the industry, as is evident by our current success." In addition to partner expansions, Tapad also invested in new talent. In February, Tapad announced Ajit Thupil as the company's first Senior Vice President of Identity, deepening the company's commitment to creating ground-breaking digital identity resolution products for brands, agencies and platforms. Tapad's investment in talent has been recognized by One World Identity's 2019 Top 100 Influencers in Identity Award and by ClickZ's 2019 Marketing Technology Awards. "At Tapad, our focus is on continuously advancing our digital identity resolution products to cater to the needs of marketers across industries," said Chris Feo, SVP of Global Data Licensing and Strategic Partnerships at Tapad. "As a part of that commitment, we are consistently growing our partner base, product features, and widening our reach on a global scale. We're excited to sustain our growth throughout 2019." To learn more about Tapad and our digital identity resolution products, visit Experian.com Open job opportunities across the globe can be found on Tapad's career page here: https://www.experian.com/careers/ About Tapad Tapad, Inc. is a global leader in digital identity resolution. The Tapad Graph™, and related solutions, provide a privacy-safe approach to connecting device identifiers to brand and marketer data, thereby allowing marketers around the world to maximize campaign effectiveness. 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. Contact us today!

The UK digital advertising market is worth £13.44bn, an increase year-on-year of 15%, reveals the 2018 IAB UK & PwC Digital Adspend Study. Report highlights The majority of all growth is coming from smartphone advertising, which has increased by £1.65bn (35%) from 2017. Smartphone advertising now represents 51% of all UK digital ad spend, up from 45% in 2017. Video is now the largest display format (£2307m), overtaking standard display banners (£1486m). Outstream/social in-feed has increased its majority in total video spend, now occupying a share of 57%, up from 52% in 2017. Social revenue now represents 23% of all digital ad spend. Growth is predicted to slow during 2019, with 5% estimated growth (+9% digital, +11% display, +9% search) compared to 15% in 2018. 2018 marks the tipping point towards a mobile-first ecosystem “For the past few years, industry commentators have been hailing the year of mobile. Each January the predictions come and the waiting commences for evidence to mark a tipping point, a shift to a mobile-first digital ad ecosystem. Well, drumroll… it was 2018! The latest Adspend report from IAB UK and PwC reveals that spend on smartphones outstripped spend on desktop for the first time last year. Brands spent 51% of total spend (which stands at £13.44 billion) on smartphones in 2018, up from 45% in 2017 – a significant milestone in the evolution of digital advertising. “This evidence shows that advertisers are increasingly thinking mobile-first. Growth in investment has historically lagged behind the amount of time spent on the device and we expect to see growth continue at a rapid pace to keep up with audience behaviour – two thirds of time spent online is now on mobile, according to UKOM. Other areas of growth highlighted by the report include video, which accounts for 44% of the total display market, while mobile video now makes up 51% of smartphone display. This is no doubt down to bigger mobile screens, better 4G and more readily available WiFi making video ads an increasingly attractive option. “Across the board, advertisers are investing in digital for longer-term brand building as well as short-term activation, with the direct-to-consumer market helping to drive this trend. What’s more, digital continues to be an accessible and popular route to market for businesses of all sizes, from leading advertisers to SMEs.” Tim Elkington, Chief Digital Officer, IAB UK Content & context crucial for attracting audiences “As people spend more and more of their time on mobile, it’s comes as no surprise that advertisers will follow where audiences are with their marketing spend. “Video has been the driving force in this growth, indicating that engaging visual content is still key in helping brands to achieve great results and to capture consumer attention in a vast sea of digital noise. “Video still has a way to go if it is to reach the level of effectiveness of traditional formats like cinema, but it will be interesting to see how the format develops over the next year or so. Ultimately, brilliant content and properly considered context are crucial for advertisers hoping to attract relevant audiences and build strong brands long term.” Kathryn Jacob OBE, CEO, Pearl & Dean Mobile-first approach driving investment in user experience “As a mobile-first approach has become the norm for many businesses, we’ve seen significant innovation and investment in the user experience that has fuelled the rise in mobile commerce. “Yet, for some years, limitations in the technology and formats available have meant that mobile advertising couldn’t always keep pace with changing consumer behaviours – delivering weaker performance when compared to desktop. “Fortunately, mobile has made huge strides in recent years. Mobile advertising affords great targeting opportunities for brands and a more interactive and immersive experience for consumers. “There is no reason to doubt this trend will continue as advertisers design their media, creative, and targeting strategy with mobile at the heart – optimising performance, enhancing the customer experience, and delivering the best results.” James Cragg, UK Managing Director, Tug New technologies to improve investment efficiency “The UK digital ad market has continued to grow despite the various challenges that the market has faced, including the current socioeconomic climate and general changes in the industry. As spend increases, it’s important to look at how media buying can be made as efficient as possible, minimising waste and maximising the return on investment. “Marketers will start to look to new technologies, like AI, to offer an impartial and more efficient approach to media buying, allowing marketers to measure effectiveness of campaigns and allocate spend accordingly.” Carl Erik Kjaersgaard, Chief Executive, Blackwood Seven Industry going from strength to strength “This significant growth in ad spend is great to see and shows that our industry is going from strength to strength. It’s especially good to see that as advertisers invest more and more in digital advertising, they’re becoming more considered in where they’re spending their money – with a large portion of the growth coming from companies that are part of IAB’s Gold Standard. “At The Trade Desk, we’ve long been ambassadors for the importance of transparency. These findings show that it isn’t just the right thing to do, but makes good business sense as advertisers increasingly choose partners who are demonstrating a commitment to best practice.” Anna Forbes, UK General Manager, The Trade Desk Advertisers embracing mobile “As consumers spend more of their time online, it’s no surprise that digital ad spend has continued its rise, up 15% to £13.4bn. With digital, in every sense, becoming further embedded in our daily lives, it is inevitable that this number is set to rise further next year. “Given the vast majority of people using their smartphone as their primary digital device, evident from site traffic stats we see across the board, the IAB report shows that advertisers have started to fully embrace this shift by following with ad spend. Over the last few years, a combination of faster wireless connectivity along with more capable devices has made it the go-to device for consumers to get online. This is set to continue over the next few years with 5G and even faster, more capable smartphones arriving (i.e. foldables) that will further cement ‘mobile’ as the main digital device to reach consumers.” Wajid Ali, Head of Paid Search, ForwardPMX Budgets must go to professionally produced content “In the IAB’s latest ‘Digital Adspend Study’ it is positive to see that outstream continues to dominate video spend, showing close to a 10% year-on-year increase. “Unsurprisingly, the study highlights that mobile is the most important distribution device (76% of all video spend is on the smartphone), and it’s great to see the format we invented dominating that space. “However, it’s now more pertinent than ever that clients and agencies invest their outstream budgets into professionally produced content and not social infeeds. Budgets must go where content is being produced, rather than aggregators and distributors, where the content is read rather than where a click happened. “We must remember how important local, national, and vertical press are to the global digital ecosystem. By unifying the best publishers at scale, delivering mobile-optimised creativity and outcome-orientated distribution, we are fighting to ensure publishers are getting their fair share of revenue in comparison to the social platforms.” Justin Taylor, UK MD, Teads UK market in robust health “The latest IAB digital ad spend report shows encouraging signs that the UK digital advertising market is in robust health, with mobile advertising continuing its upward trend. “The rise of up-and-coming ad formats like Shopping Ads, Google’s Responsive Search Ads, and Facebook Messenger Ads show that advertisers are looking for ways to capture consumer attention in the evolving digital landscape. As a result, the lines across search, social, and e-commerce are more blurred than ever with the introduction of features like Checkout for Instagram and Shopping ads on Google Images. Furthermore, with the rapid growth of Amazon’s ads business, e-commerce has quickly emerged as a third pillar of digital advertising, making it vital for marketers to have a complete view of the customer journey across channels and devices, if they hope to more accurately understand campaign performance and attribution.” Wesley MacLaggan, SVP of Marketing, Marin Software Digital identity resolution essential in understanding customer journey “Last year’s figures show that UK ad spend is starting to mirror the behaviour of consumers who, according to UKOM data, spend two-thirds of their time online on a smartphone. The fact that mobile ad spend now surpasses that of ad spend on desktop highlights marketers’ understanding that digital identity resolution is essential, not a nice-to-have. “Appreciating the cross-device behaviours of consumers allows brands to gain a better understanding of the customer journey and build stronger relationships with their audiences long term.” Tom Rolph, VP EMEA, Tapad, a part of Experian Contact us today!

OpenAudience promises the targeting capabilities of a walled garden but without the restrictionsOpenX has lifted the lid on a targeting solution it claims will offer people-based advertising opportunities outside of the industry’s walled gardens such as Facebook and Google. Dubbed OpenAudience, the supply-side programmatic player claims the new offering is powered by proprietary data assets and is supplemented by data partnerships with partners such as LiveRamp and Tapad, a part of Experian. Initially available in the U.S., OpenAudience has a user graph of 240 million monthly users and is currently being tested with multiple marketers with a general rollout planned for the third quarter of 2019. Speaking with Adweek, OpenX CEO Tim Cadogan said the rollout would help differentiate it among its peers as for the most part ad exchanges have marketed themselves based on their impression count, not necessarily addressable audiences. Compare this with Google and Facebook, both of whom account for almost 60% of U.S. ad spend, although this is disproportionate to the amount of time spent with their properties, according to Cadogan. “The thing that has given Facebook and Google so much power is that they have people-based systems [for ad targeting] that are simple to use and operate with a massive scale that are effective, and programmatic hasn’t kept pace with that,” he said. Cadogan cited the findings of a further study by eMarketer, which indicated that marketers are increasingly reliant on such walled garden players for their online inventory supply with the latest launch geared towards capitalizing on that. The latest launch is the culmination of the California-based company’s recent strategic overhaul, namely its attempts to get to grips with an identity-based solution that provides options outside of the walled gardens. Also speaking with Adweek was Todd Parsons, OpenX’s chief product officer, who offered further insight into how OpenAudience operates including how it uses its recently sealed relationship with Google Cloud Platform and machine learning to ape the efficacy of walled garden advertising solutions. “We had to build a matching technology, which made it possible for us to talk about monthly active users instead of talking about cookies or devices,” he explained. “And it took several quarters of staffing up with the right people from the consumer data and identity space.” OpenAudience’s matching technology works by using the identity and cookie matching capabilities of cross-device specialist Tapad and data onboarder LiveRamp to formulate a persistent, deterministic ID which can then be used to match advertisers with audiences on its ad exchange. “So, the idea isn’t for us as a company to put our future into one provider,” added Parsons. “It is to provide a matching technology that uses the best of several.” OpenAudience will also include involve additional tie-ups to offering further demographic information on the 240 million monthly U.S. users such as location, etc., which is currently in testing. “We felt like we needed to be very different about enabling marketers and publishers to activate against that data,” added Parsons. He further added that OpenX wants to rival Facebook’s levels of service when it comes to helping publishers monetize audiences on the social network, except this time on the open web. “No one has actually pushed identity and consumer data into the hands of publishers in a way that you might unify the view of audiences across many websites.” OpenX’s Cadogan summed up the OpenAudience offering and how it may look to advertisers when he said, “Imagine the open web is one publisher, and this lets buyers look at it as a single entity and market to them accordingly.” Contact us today!