ChatGPT’s share of AI assistant prompt volume fell from 70% to 50% between January and June 2026, according to Comscore’s newly released Q2 2026 AI Intelligence Report, even as the overall category of AI assistant usage kept expanding. Claude’s share of prompt volume grew from 2% to 11% over the same period, and Google’s Gemini nearly doubled, from 17% to 30%.

The report, based on Comscore’s consumer panel data, also found that AI assistant adoption is now growing faster on mobile than desktop, up 25% versus 12% since the start of 2025, and that women continue to lead usage on mobile specifically. The firm frames the shift as evidence that no single AI experience can be treated as a stand-in for “AI search” the way ChatGPT was for most of 2025.

“As competition among AI assistants intensifies and prompt volume shifts across platforms, brands and publishers can no longer assume that a single AI experience defines the market,” said Smriti Sharma, Chief Analytics and Technology Officer at Comscore. “Understanding where consumers are turning with their questions, which sources AI cites in response, and how those interactions convert into measurable business outcomes is becoming essential to any brand’s growth strategy in this new era of AI-influenced discovery.”

The original insight for marketing leaders is a measurement one: any team that built its AI-visibility tracking or brand-monitoring tooling around a single assistant six months ago is now missing close to half the category by prompt volume. Fragmentation across ChatGPT, Claude, and Gemini also means citation and referral patterns need checking per assistant, not once, since Microsoft’s own data on AI cutting publisher clicks already showed how differently a single assistant can behave from the search engine it sits beside. Comscore’s numbers add the missing piece: that behavior is not uniform across assistants either, and a measurement plan built for one will undercount or miscount the rest, a gap this publication’s earlier reporting on AI chatbots and purchase behavior flagged from the consumer side of the same trend.

Source: Comscore