Seven-month study finds lower cross-platform consistency in the UK, stronger reliance on news publishers, and significant gaps between brand mentions and citations

Semrush, an Adobe company, has released a new edition of its 2026 AI Visibility Index, examining how major AI platforms surface brands and information sources in the United Kingdom and the United States. Presented at Spotlight London, the research finds that AI visibility varies considerably by market, platform, and industry, challenging the idea that brands can rely on a single global strategy to improve their presence in AI-generated answers.

The study analyzed seven months of data from January through July 2026 across ChatGPT, Gemini, and Google AI Mode. It used fixed monthly datasets of 2.5 million UK prompts and 25 million US prompts derived from Semrush search data, alongside a larger variable dataset of Google AI Overviews results for real search keywords.

Across the four AI platforms studied, agreement on the brands mentioned and sources cited was lower in the UK than in the US. Any two platforms shared an average of 63 to 70 of their top 100 mentioned brands in the UK, compared with 70 to 78 in the US.

The findings suggest that brands need to measure visibility separately across markets and platforms rather than assuming that strong performance in one environment will translate to another.

AI Visibility Depends on Market and Platform

The Index found that different AI platforms produce distinct visibility patterns. Gemini mentions more distinct brands per answer than ChatGPT, while ChatGPT cites the most sources per answer among the four platforms studied.

The report also identified greater fragmentation in the UK, where a larger proportion of leading domains appeared on only one AI platform. Google AI Overviews showed particularly low overlap in brand mentions with other platforms across the seven-month period.

These differences mean that brands may need to adapt their content and visibility strategies to the audiences, questions, and source ecosystems associated with each market and AI platform.

Marissa Dacay, global vice president of enterprise marketing at Adobe, said brands need to optimize their own content for the expectations of different markets while also developing relevant third-party signals.

The commercial implications are growing as AI becomes part of the customer discovery and purchasing journey. Adobe data cited in the report indicates that AI-referred visitors convert 60% better than non-AI traffic and generate 53% more revenue per visit.

A Core Group of Brands Dominates AI Visibility

The study identified a group of brands that consistently appeared among the top 100 mentioned brands across all four AI platforms in every month analyzed. The report calls this group the Universal Core.

Twenty-four UK domain records met the criteria, compared with 36 in the US. Only 15 domains were shared between the two markets, including Adobe, Apple, Amazon, Google, LinkedIn, Microsoft, Reddit, TikTok, and YouTube.

The UK-specific group was heavily weighted toward retail. Six of its nine unique domains were ecommerce or retail brands: Amazon UK, Argos, Asda, eBay UK, Marks & Spencer, and Tesco. BBC, Nike, and TripAdvisor UK completed the group.

By contrast, the US-specific group covered a broader range of sectors, including automotive, sports, entertainment, and retail.

Andrew Warden, global vice president of marketing and chief marketing officer at Semrush, said AI is becoming a decision layer that influences how customers discover brands, compare options, and make purchases. He emphasized that the sources and brands shaping decisions in the UK are not identical to those in the US.

UK AI Answers Rely More Heavily on News Publishers

News publishers played a more prominent role in UK AI answers than in the US, according to the Index.

On ChatGPT, news websites accounted for an average of 29.5% of citations among the 100 most-cited UK domains, compared with 19.6% in the US. On Gemini, news was the leading UK source category every month, accounting for between 16.6% and 23.0% of top-100 citations.

The source mix also differed by platform. In the UK, trip-planning websites and online marketplaces followed news on ChatGPT. In the US, online learning and streaming platforms were the next prominent categories.

The findings highlight the role of third-party sources in AI visibility. A brand’s presence in AI-generated answers can depend not only on its own website and content but also on coverage and references from publishers, marketplaces, communities, and forums.

For marketing teams, this creates a broader visibility challenge that extends beyond optimizing owned content to understanding the independent sources influencing AI-generated responses.

Brand Mentions Do Not Guarantee Citations

The report distinguishes between being mentioned in an AI-generated answer and being cited as a source. These represent different forms of visibility, and brands cannot assume that prominence in one guarantees prominence in the other.

Across 22 categories and four platforms, fewer than half of the top 100 mentioned brands also appeared among the top 100 cited domains in every month studied, in both markets. In the UK, the average overlap ranged from 36.7 to 45.3 domains out of 100, depending on the month.

The differences can be pronounced even among direct competitors. In July, Tesco ranked 25th among ChatGPT’s most-cited UK domains, while Asda ranked 606th. On Gemini, the two retailers were closer, ranking 29th and 60th, respectively.

The comparison illustrates why marketers need to evaluate both brand mentions and source citations across individual platforms rather than relying on a single AI visibility score.

Additional Findings Highlight Platform-Specific Differences

The Index identified several other trends affecting how brands appear in AI-powered discovery:

• Different brand coverage: Gemini mentions more distinct brands per answer than ChatGPT, while ChatGPT cites the most sources per answer and Gemini the fewest.

• Distinct Google AI Overviews results: Brand mention overlap was consistently lowest on Google AI Overviews compared with the other platforms. Its source overlap with ChatGPT was also the lowest among platform pairs in both markets.

• Concentrated source influence: In the UK, the ten leading source domains on Google AI Mode accounted for between 23.2% and 35.8% of citations among its 10,000 most-cited UK domains during the study period. On ChatGPT, the equivalent share ranged from 12.8% to 15.4%.

• Sector-specific visibility: The report found meaningful differences across categories such as real estate, finance, industrial markets, and sports, reinforcing the need for category-specific benchmarks.

Taken together, the findings suggest that AI visibility is not a single, uniform ranking. Brands seeking to improve their presence in AI-generated answers need to account for local market differences, platform-specific behavior, industry context, and the third-party sources that influence discovery and evaluation.