Method
- When: 3 October 2026, in three rounds.
- Where: United States, United Kingdom, Germany, Austria, Switzerland, France, Spain, Italy, Poland, Netherlands.
- Industries: dentists, med spas and aesthetic clinics, lawyers, plumbers, roofers, HVAC, movers, cleaning companies.
- Engines: ChatGPT and Gemini as seen in their web interfaces (collected through DataForSEO), Google AI Mode, Google Search with its local results, and Perplexity’s API. ChatGPT was asked up to five times per question, Gemini up to three.
- Questions: in the local language, with the city written into the question. Country was set for each engine; the city could not be set for ChatGPT.
- Business checks: for 23 businesses, we asked each engine about the business by name and compared its answers with the business’s website and Google profile.
- Overlap is measured as Jaccard similarity: shared names divided by all names in the two lists.
Limits
The samples are small and all from one day. Answers for logged-in users, paid plans or a user’s own location can differ, and we did not check Copilot, Claude or Grok. Business names are anonymized here; we report patterns, not judgments about specific companies. We will repeat these measurements on a schedule and publish changes.
Larger studies agree on the main points: BrightLocal’s analysis of 200,085 local prompts found that businesses present in Google Maps results appear in only about a third of ChatGPT answers, and that asking the same question again repeats only 20–33% of named businesses (September 2026).
Use this data
You can quote and chart these findings with a link to this page. Journalists and researchers can ask us for the per-question counts.
