Comscore on September 22, 2026 published its Q2 2026 AI Intelligence Report, a 47-page document built on its US opt-in panels, which puts ChatGPT at 50% of AI prompt volume in June 2026, down from 70% in January, while Google's Gemini climbed from 17% to 30% and Anthropic's Claude from 2% to 11%. The same report tracks AI summaries on 39.4% of Google desktop searches, sponsored placements inside ChatGPT shopping conversations and the share of online shoppers who open an assistant before they buy.

In Short

A company that watches what a large group of volunteers do online found that people in the US are spreading their questions across more AI assistants, with ChatGPT handling half of all questions in June against 70% in January, and Gemini and Claude picking up most of the difference. That matters to any brand or website that wants to be mentioned in AI answers, because the audience is no longer gathered in one place and paid ads now appear in a fast-growing share of ChatGPT shopping chats. What changes is the map of where AI attention sits: spread over several assistants, sitting next to more paid placements, and measured by firms whose own summaries do not always match their charts.

Prompt volume moves away from the leader

The pie charts at the centre of the report are blunt. In January 2026, according to Comscore, ChatGPT accounted for 70% of all prompt volume across the seven assistants it tracks, Gemini for 17%, Microsoft's Copilot for 5%, xAI's Grok for 3%, Claude for 2%, and DeepSeek and Perplexity for 1% each. By June, the order had been rearranged below the top slot. ChatGPT held 50%, Gemini 30% and Claude 11%. Copilot stayed at 5%, DeepSeek edged up to 2%, Grok slipped to 1% and Perplexity rounded to zero. Both charts sum to 99% because of rounding.

Gemini and Claude between them added 22 percentage points in five months. Claude's share rose 5.5 times on the rounded figures, which Comscore's release describes as "more than fivefold". Grok and Perplexity were the only other assistants to lose ground, Grok dropping from 3% to 1%.

Smriti Sharma, Chief Analytics and Technology Officer at Comscore, framed the shift in commercial terms. "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," Sharma said in the release, which was issued from New York at 8:00 a.m. Eastern Time. "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 prompt figures sit awkwardly beside an audience number Comscore published less than three weeks earlier. When the company expanded its AI Intelligence product to sponsored chat advertising on September 3, it said ChatGPT accounted for approximately 69% of unique visitors in the AI assistant category in June 2026. Reach and volume, in other words, now diverge by about 19 points for the same month. ChatGPT still touches most assistant users; it no longer receives most of what those users type.

A spring peak, then a summer dip

Behind the shares sit monthly counts of desktop conversations, and here the report's own framing needs careful reading.

Comscore's release states that ChatGPT "reached 168 million desktop conversations in June 2026". The chart behind that sentence starts at 157 million in March 2025. Its bars for March and April 2026 stand near 240 million on the right-hand axis, and a draft slide in the appendix labels June 2025 at 170 million. On those figures, June 2026 was slightly below June 2025 and roughly 30% below the spring high. The slide title reads "ChatGPT Holding Steady with YOY Growth in Q2". Across the full quarter the claim can hold, since the April and May 2026 bars sit well above their 2025 equivalents; the June comparison runs the other way.

Claude's curve is steeper in both directions. Desktop conversations stood at 1.124 million in October 2025, according to Comscore, rose to about 40 million in April 2026 and then fell to about 32 million in May and 22.304 million in June. The release calls this "plateauing at 22.3 million in June". A move from roughly 40 million to 22.3 million is a decline of about 45%, not a plateau. The slide itself is more candid, titled "Summer Tempers Claude's Meteoric Rise". The June figure remains about 20 times the October level, and the line tracking Claude's desktop users held close to 4 million from April through June, so the drop came from fewer conversations per user rather than fewer users.

Those users lines match earlier Comscore data. Claude's reads about 2.7 million for March 2026, close to the 2.66 million US desktop unique visitors in the company's March 2026 chatbot rankings, and ChatGPT's sits near the 33.86 million recorded there.

Gemini's desktop conversations rose from 8 million in May 2025 to 89 million in June 2026, according to Comscore, an elevenfold increase. The bars peaked at roughly 104 million in April before easing, a pattern the slide calls an "Early-Summer Pause". Copilot moved from 9 million to 12 million over the same window, with peaks near 14 million in November and December 2025 and again in March 2026. The Copilot chart carries the subtitle "Total Users & Conversations on Google Gemini (Desktop)", a labelling error the report does not correct.

Why Claude's share outruns its conversation count

How can an assistant with 22 million desktop conversations hold 11% of prompts? Comscore measured the average number of prompts per conversation in June 2026 at 5.4 for ChatGPT, 6.2 for Gemini, 6.9 for Copilot and 9.1 for Claude. Claude's conversations were 13% of ChatGPT's in June. Its implied prompts, at 9.1 per conversation, come to about 203 million, or 22% of ChatGPT's roughly 907 million.

The arithmetic goes further. Multiplying each assistant's June desktop conversations by its prompts per conversation, and setting aside the 3% held by DeepSeek, Grok and Perplexity, produces shares of 50.4% for ChatGPT, 30.7% for Gemini, 11.3% for Claude and 4.6% for Copilot. All four land within a point of the published figures. That strongly suggests the prompt-volume series is built on the same US desktop panel, although the pie chart's source line reads only "Comscore Custom IQ data, US" and the release calls it "Comscore panel data".

Other panels have drawn a similar profile. Similarweb's 2026 generative AI landscape report, published in July, placed Claude at the far end of both median prompt length and prompts per session. Similarweb's worldwide traffic series had ChatGPT at 52.7%, Gemini at 27.3% and Claude at 8.9% as of late May, and Datos recorded Claude rising from 3.58% to 8.54% of US desktop AI tool users between January and March. None of those units is interchangeable with Comscore's. They point the same way.

Reach widens on mobile

In June 2026, 35% of US desktop users and 29% of mobile users visited an AI assistant, according to Comscore, against 25% and 12% in January 2025. Mobile reach therefore rose 17 percentage points and more than doubled, while desktop added 10 points.

The release describes the same finding differently. It states that "the rate of growth on mobile is now outpacing desktop, with adoption of AI assistant up 12% and 25% respectively since the start of 2025". The 12% and 25% are the January 2025 starting levels shown in the report's chart, not growth rates. The direction of the sentence is right; its numbers are not.

Multiplatform visitors, which combine desktop and mobile, grew for all four major assistants between June 2025 and June 2026: ChatGPT from 59 million to 99 million, Copilot from 32 million to 36 million, Gemini from 18 million to 30 million and Claude from 2 million to 10 million. The desktop and mobile splits vary sharply. Gemini's desktop audience tripled from 4 million to 12 million while its mobile audience rose from 14 million to 19 million. Claude reached 7 million on desktop and 3 million on mobile.

These desktop totals do not reconcile with the users lines on the conversation charts. The multiplatform slide puts ChatGPT at 58 million desktop visitors in June 2026, while the conversation chart's users line sits near 30 million for the same month. The multiplatform slide carries a footnote stating that Comscore's generative AI data includes both Dedicated AI-Powered entities and Partially AI-Powered entities, entities that "may only incorporate AI as a supplemental feature", which may account for part of the gap. The report does not say.

Older users, women on mobile, social overlap

Every age group grew. On desktop, visitors aged 65 and over rose 112% year on year and those aged 55 to 64 rose 69%, against 17% for under-18s and 22% for 18 to 24 year olds. On mobile, the 65-plus group grew 108% and 55 to 64 year olds 98%.

Gender indexes, where 100 equals representation in the overall internet population, split by device. Women over-index on mobile for ChatGPT at 110, Copilot at 119 and Gemini at 115, while men over-index on desktop for the same three services at 114, 117 and 122. The largest movement came at Gemini on mobile, where the female index went from 94 in June 2025 to 115 a year later and the male index from 106 to 85.

Comscore also measured AI assistant use among desktop visitors to three large social platforms. Between June 2025 and June 2026 the figure rose from 32% to 53% for TikTok, from 32% to 47% for Meta and from 30% to 39% for YouTube. The slide's source note refers to search data covering the first quarter of 2024 through the first quarter of 2026, which does not match the June comparison shown.

AI summaries on 39.4% of Google desktop searches

The share of Google desktop searches carrying AI Overviews rose from 25.8% in July 2025 to 39.4% in June 2026, according to Comscore's custom search data. The climb was uneven: 24.4% in August 2025, 30.2% in October, 34.9% in December, 36.1% in February 2026, a dip to 33.6% in March, then 35.8% in April, 35.4% in May and the June high. Bing searches carrying Copilot Search moved from 11.8% to 17.3% over the same twelve months, peaking at 17.4% in April 2026.

Total US desktop search volume across Google, Microsoft, Verizon Media and Ask properties reached 77 billion in the second quarter of 2026, according to Comscore, against 76 billion a year earlier and 71 billion in the second quarter of 2024. The report presents this as 8% growth against 2024; against 2025, the increase is about 1%. That slide's source note again cites a first-quarter date range while its bars are labelled as second quarters.

The same slide annotates the timeline with "Bing launched Copilot Search in April 2024". Microsoft unveiled Copilot Search in Bing on April 4, 2025, a year later. The companion annotation, that Google rolled out AI Overviews in May 2024, is correct.

The traffic consequences of that rising share have been measured independently. A randomised field experiment with 1,065 desktop Chrome users found that AI Overviews cut outbound organic clicks by 39.8% and raised zero-click searches by 34.5% when the feature appeared. At 39.4% coverage, the searches exposed to that effect now amount to roughly four in ten Google desktop queries in Comscore's panel.

Who gets cited

Comscore ranked the domains most often cited in AI summaries across Google and Bing in June 2026, by category. In entertainment, YouTube was the cited source in 26% of the searches Comscore ranked, Wikipedia in 25%, Reddit in 19%, Fandom in 17% and IMDb in 12%. In sports, Wikipedia led at 24%, ahead of ESPN and Go.com at 20% each. Retail showed the widest gap between the first two: YouTube at 23%, Amazon at 14%, Reddit at 12% and Wikipedia at 11%, with eBay and Walmart at 3% and Home Depot and Target at 2%.

Financial services looked different. No domain passed 9%: YouTube led at that level, followed by NerdWallet, Reddit and Bankrate at 7% each, Forbes at 6% and Chase and Fidelity at 5%. The Internal Revenue Service's site appeared at 2%. In this regulated category the citation set is more fragmented, and specialist publishers such as NerdWallet and Bankrate sit level with the platforms. The pattern echoes a 2025 Pew Research study in which Wikipedia, YouTube and Reddit together accounted for 15% of sources in AI summaries, and SISTRIX's finding that YouTube took 40% of citations in Google's German AI Mode after its October 2025 debut.

Assistants inside the purchase path

The report's commerce section follows desktop purchasers at the top 100 US retail sites and records whether they visited an AI assistant within 30 days of buying, in the same session, or within five minutes. In the second quarter of 2026, the figures were 34%, 22% and 3% for books, music and video; 35%, 21% and 2% for toys and hobbies; 39%, 21% and 1% for office supplies and business machines; and 35%, 26% and 4% for home and living.

A narrower measure counts only conversations about the category being bought. In the same session as a purchase, 14% of home and living buyers had an on-topic AI conversation, as did 12% of books, music and video buyers, 10% of office supply buyers and just 4% of toy and hobby buyers. Within 30 days, 26% of home and living purchasers used AI for conversations related to that category.

The trend lines move in different directions. Home and living rose from 33% to 35% on the 30-day measure between the first and second quarters of 2026, and from 22% to 26% within the same session. Toys and hobbies fell from 40% to 35% on the 30-day measure but rose from 17% to 21% in the same session.

One headline overstates its data. The home and living slide states that assistants "Reached 35% of Home & Living Purchasers as they were making their purchase". The 35% is the 30-day figure; the same-session figure is 26%. The chart beneath that headline is also labelled "Desktop Toy & Hobby Purchasers". The toys slide uses its same-session figure, 21%, consistently. Comscore's footnotes list the chatbots in this analysis as tools from OpenAI, Google, Anthropic, Perplexity, X, Meta and DeepSeek. Microsoft is not named.

Brand mentions grew quickly over a short window. Fashion brand mentions in AI responses rose 123% and health and beauty brand mentions 150% between January and March 2026, according to Comscore. The fashion figure is based on a peer set of Adidas, Gap, Levi's, LVMH, Macy's, Nike, Nordstrom, PVH, Ralph Lauren and Tapestry. No peer set or absolute count is given for health and beauty.

The sponsored layer

Comscore's hotel data repeats what it disclosed on September 3: sponsored ads appeared on 6% of hotel-related ChatGPT prompts with source links in March 2026, 14% in April and 24% in May. The report names Airbnb, Booking.com, Expedia.com and Priceline.com among travel brands observed in sponsored placements.

The retail figures are new, and they run a month further. The share of retail category-related ChatGPT conversations carrying sponsored ads, measured on PCs in the US, went from 3% in March 2026 to 4% in April, 18% in May and 47% in June for video games and consoles. Toys and hobbies went from 5% to 12%, 14% and then 24%. Books, music and video moved from 9% to 12%, fell to 8% in May and reached 22% in June. All three categories rose sharply between May and June.

Those numbers sit alongside other measurements of the same inventory that use different denominators. OpenAI's pilot opened on February 9, 2026. Similarweb put sponsored ads in 26% of ChatGPT responses on Free and Go plans in data published in August, while Adthena counted ads on 4.47% of US queries between March and May. Sensor Tower found shopping and retail's share of US ChatGPT ad spend falling from 37% to 21% between April and August. A smaller slice of a fast-growing budget can still fill more conversations, so Comscore's June figures do not contradict Sensor Tower's. The June jump is, however, a single month of data, and Comscore does not say how many conversations each category contains.

The format is also changing under the measurement. OpenAI began testing Sponsored Agents on September 16, an ad unit that opens a separate conversation with an advertiser's agent. Comscore's sponsored measurement in this report covers ChatGPT only. Claude, the assistant with the fastest share gain, carries no ads at all after Anthropic committed on February 4 to keeping it ad-free.

Sources outnumber citations

The travel analysis separates two layers that are often merged. Assistants built on retrieval-augmented generation pull in pages as source links, and a smaller set surfaces as cited links that users see. Across lodging-related AI responses between December 2025 and May 2026, measured on PCs in the US, Tripadvisor appeared as a source in 61% of responses, Hotels.com in 50%, Expedia in 46%, Booking.com in 33%, Trip.com in 22%, Kayak in 20% and Condé Nast Traveler in 18%. Among hotel brands, Marriott appeared in 14%, Hilton in 11%, IHG in 8% and Hyatt in 5%. Airbnb and Vrbo were at 3% each.

Citation shares are much lower. Tripadvisor fell from 61% as a source to 21% as a citation, Hotels.com from 50% to 18%, Expedia from 46% to 16% and Booking.com from 33% to 9%. Kayak and Marriott were each cited in 6%, Hilton in 5% and IHG in 3%.

Comscore then divides cited share by source share to produce relative citation visibility, which it describes as a relative index rather than a prompt-level measure. On the rounded figures, Hilton converts about 45% of its source presence into citations, Marriott 43% and IHG 38%, ahead of Hotels.com at 36%, Expedia at 35% and Tripadvisor at 34%. Booking.com, at 27%, trails. Marriott, Hilton and IHG are consulted less often than the aggregators but, on this measure, cited more readily. Hyatt, plotted near 0.26 on Comscore's matrix, does not share the pattern.

Panel, definitions and loose ends

The measurement framework rests on three opt-in panels: desktop, mobile and a home router panel that Comscore abbreviates as THP. The company describes "fusing panel & census data" with projections and market weightings. Desktop figures cover persons aged two and over and mobile figures adults aged 18 and over. The report does not disclose panel sizes, margins of error or weighting targets, and it makes no reference to Media Rating Council accreditation for these series. Comscore began measuring generative AI search in November 2023.

The document also carries leftover production notes. Many slides carry an orange "Updated" tag, an appendix slide is marked "New Design: TBD", and a note on the gender slide refers to updating "slides 8, 11, and 13-14 with the Jun'26 data". Together with the mislabelled Copilot chart, the mismatched source notes and the Copilot Search date, these slips do not overturn the headline trends, but they leave several captions at odds with the charts they describe.

Why the fragmentation matters

For marketers, the report's central finding is that the AI audience and the AI workload have separated. ChatGPT still reaches most assistant users and hosts the only sponsored inventory Comscore measures, yet half of the prompt volume in Comscore's US panel now goes elsewhere, and 11% goes to an assistant that sells no ads. Visibility inside assistants has become a multi-platform measurement problem at a time when an IAB framework published in August found only 16% of brands systematically track AI visibility.

Comscore's contribution to that tracking is the conversation and prompt layer, together with purchase data showing that between a fifth and a quarter of desktop buyers in four retail categories opened an assistant in the same session as their purchase. How much of that behaviour survives into the third quarter, after spring peaks in conversations at all three leading assistants, is a question the next edition of the report will have to answer.

Timeline

Summary

Who: Comscore, the US media measurement company, published the report with commentary from Smriti Sharma, its Chief Analytics and Technology Officer. The data covers OpenAI's ChatGPT, Google's Gemini, Anthropic's Claude, Microsoft's Copilot, DeepSeek, Grok and Perplexity, along with Google and Bing search, retail purchasers and travel brands.

What: The Q2 2026 AI Intelligence Report found ChatGPT's share of AI prompt volume falling from 70% to 50% between January and June 2026 as Gemini rose to 30% and Claude to 11%, desktop conversations at all three peaking in the spring, AI Overviews on 39.4% of Google desktop searches, sponsored ads in 47% of ChatGPT video game conversations in June, and between 21% and 26% of desktop buyers in four retail categories visiting an assistant in the same session as a purchase. Several captions and release statements do not match the underlying charts.

When: Comscore released the report on September 22, 2026. Its data runs from January 2025 to June 2026, with prompt-volume comparisons for January and June 2026.

Where: The measurements cover the United States, drawn from Comscore's desktop, mobile and home router panels. Sponsored-ad and travel citation data is limited to PC usage.

Why: Prompt volume is fragmenting across assistants while sponsored placements spread inside ChatGPT and AI summaries cover a growing share of search, which changes where brands, publishers and advertisers can be seen and how that visibility can be measured.