Comscore Finds ChatGPT Losing Prompt Share as AI Discovery Splinters

AI discovery is becoming less synonymous with ChatGPT. Comscore’s newly released Q2 analysis found ChatGPT’s share of AI prompt volume fell from 70% in January to 50% in June, while Gemini and Claude gained ground. For publishers, the shift raises the stakes of knowing not just whether an AI tool uses their work, but whether people ever see the attribution or reach the source.

The numbers do not describe a shrinking chatbot market. Comscore says overall use is growing as prompts are distributed across more services. In June, 35% of desktop users and 29% of mobile users visited an AI assistant, up from 25% and 12%, respectively, in January 2025. ChatGPT still recorded 168 million desktop conversations in June and 99 million in multiplatform visitation, up from 59 million a year earlier.

One audience habit, several answer engines

Prompt share measures the portion of prompts handled by each assistant, rather than the absolute number of conversations. Gemini’s share nearly doubled from 17% to 30% over the first half of 2026; Claude’s grew from 2% to 11%. ChatGPT retained the largest reported share, but not the same dominance it held at the start of the year.

The platform figures reinforce that picture, though they are not directly interchangeable with prompt share. Gemini desktop conversations rose from 8 million to 89 million over the year before June. Claude climbed from 1.1 million desktop conversations in October 2025 to nearly 40 million in April, then eased to 22.3 million in June. Comscore based the report on opt-in panel data covering between 500,000 and 1 million respondents.

Search is also answering before the click

The change is not confined to standalone assistants. Google desktop searches that displayed an AI Overview rose from 25.8% in July 2025 to 39.4% in June 2026, according to Comscore. An Overview can answer a query on the results page, creating another route by which people may receive information without visiting the publisher that produced it.

That makes the distinction between sourcing and citation more consequential. Sourcing is the wider pool of material an assistant retrieves while developing an answer. A citation is the smaller set of visible links or attributions attached to the final response. A source can inform an answer without being visibly credited, and a visible citation does not necessarily produce a referral or revenue.

A source can be used without being seen

Comscore’s travel example puts a number on the gap: Tripadvisor accounted for 61% of travel sourcing by AI platforms but only 21% of citations. The result is not a general rule for every publisher or category. It does show why citation counts alone can miss substantial use of a site’s material, while source counts alone can overstate its public visibility.

The practical implication is a more complicated dashboard, not a simple replacement metric. Comscore’s analysis argues that publishers and marketers should measure sourcing, citations, referrals and revenue across assistants rather than optimize only for ChatGPT. As AI answers spread across more products and search surfaces, the unresolved question is which of those signals will prove most valuable—and to whom.