Being named by ChatGPT is not the same as being sourced by it. That is the headline lesson from Semrush’s second 2026 AI Visibility Index, which adds a UK benchmark for the first time. The report tracks mentions and citations across ChatGPT, Gemini, Google AI Mode and Google AI Overviews from January to July 2026.
The Tesco-Asda gap in ChatGPT citations
Tesco and Asda both made every platform’s top 100 for brand mentions in every month. In July, their mention ranks were nearly identical: 9 and 8 on ChatGPT, and 24 and 18 on Gemini. But citations tell a different story. Tesco ranked as ChatGPT’s 25th most-cited UK domain, while Asda sat at 606th. On Gemini, the two were much closer at 29th and 60th.
Across the whole study, fewer than half of the top 100 mentioned brands also made the matching top 100 citation list. The UK overlap ranged from 36.7 to 45.3 domains out of 100; the US from 41.4 to 47.4. ChatGPT showed the lowest overlap in both markets.
Why every AI platform tells a different story
The four platforms do not agree on sources. Any two platforms shared 63 to 70 of their top 100 mentioned brands in the UK on average, against 70 to 78 in the US. That means a brand can look strong in one AI answer engine and invisible in another. Google AI Overviews had the most distinctive brand mix, sharing the fewest top-100 brands with every other platform.
There is also a structural divide. ChatGPT carried 12.5 to 22 source entries per answer in the UK, while Gemini carried only 1.6 to 4.4. Gemini named more distinct brands per answer, but ChatGPT was far more likely to show source links. If your brand is absent from ChatGPT’s sources, it may still be named; if it is absent from Gemini’s sources, it may not be shown as a source at all.
The One-Way Door
Semrush calls the strangest pattern the One-Way Door: domains in all four platforms’ top-100 mention lists while sitting outside all four top-500 citation lists. The reverse is rare. In the UK, 3 to 9 domains sat in that position each month, with zero in the reverse. Ford is the US example: in July ford.com ranked 18th for mentions on ChatGPT but 1,055th for citations.
This is not a data oddity; it is a warning. Brands can be famous inside AI answers and still not be used as the source of those answers.
What UK marketers should do
- Measure mentions and citations separately. A mention is visibility, but a citation is the AI equivalent of a link. They need different audits.
- Track each platform independently. Your position can shift sharply between ChatGPT, Gemini, AI Mode and AI Overviews.
- Build source pages AI tools can cite. If competitors are being cited and you are not, check robot access, content structure and third-party descriptions.
Semrush is blunt: a chatbot’s claim that it can reach a page is not a technical test. Treat AI visibility as an SEO problem, not a brand-awareness problem.
Source: PPC Land
