Definition
AI visibility is the degree to which AI answer engines (ChatGPT, Perplexity, Google AI Overviews, Claude) can find, understand, cite and recommend a brand when users ask relevant questions. Unlike search rankings, AI visibility is measured across mentions, citations and sentiment inside generated answers rather than positions on a results page. A site can rank well in classic search yet be invisible to AI engines if its content lacks crawl access for AI bots, machine-readable structure, or quotable evidence. In practice, teams measure AI visibility with three numbers: mention rate (how often the brand appears in sampled answers), citation rate (how often its pages are linked as sources), and sentiment (how the brand is described when it does appear). BrandGEO's audit adds a fourth, upstream layer — whether your site is even retrievable by the crawlers those engines depend on — because a brand cannot be recommended from pages the engines never saw.