Checking one AI chatbot shows you a tiny slice of the web
Almost three quarters of the sites cited in a new study turned up in just one AI tool.
Asking ChatGPT whether your business shows up in AI answers tells you almost nothing about the other tools. A study from Prefer, shared by Alex Groberman, ran the same 80 questions through ChatGPT, Perplexity, Gemini and Claude, three times each. That produced 960 answers and 1,329 different cited websites, and 966 of those sites appeared in only one of the four tools. Just 29 appeared in all four.
The tools barely overlap
They do not even cite the same number of sources. Perplexity averaged 19.48 sources per answer, Gemini 8.64, Claude 4.58 and ChatGPT just 3.05. Across the 240 answers each one produced, Perplexity cited 748 different websites and ChatGPT cited 218.
The gaps show up in individual sites too. Reddit was the most cited site in the study, appearing in 207 of the 960 answers, but Claude cited it zero times. Gemini cited YouTube in 113 answers while the other three cited it zero times. Perplexity cited LinkedIn in 73 answers, Claude twice, ChatGPT and Gemini not at all.
Asking twice gives different answers
The researchers asked the same questions three times within seconds, and the cited sites still changed. Average overlap between repeat runs was 96% for Perplexity, 68% for Claude, 37% for ChatGPT and 35% for Gemini. So one search proves very little in either direction.
As Groberman put it, building a strategy on a single check is building it "around a screenshot".
What this means for your site
One caveat worth knowing. The 80 questions were all about AI search, GEO and AEO, so a plumber, a clinic or a shop could see a very different mix of sources.
The fragmentation was heaviest among smaller sites. Among the 25 most cited sites, 23 appeared across three or four of the tools, and five of the top 10 appeared in all four. Sites that lots of people trust travel between the tools. Everything else does not.
If you check your AI visibility, check it across more than one tool and ask more than once. If you only have time for one thing, spend it on content that answers the questions your buyers actually ask, plus credible mentions and links from other sites, since that is what showed up everywhere rather than in one place.
Almost 73% of the websites cited across ChatGPT, Claude, Gemini and Perplexity appeared in just ONE of them.
if you ask ChatGPT one question once and do not see your company, that does not necessarily mean you never appear
Be the person who already knew
One email a day. Under three minutes. You will hear about a Google change before it shows up in your traffic.