AI referral traffic doubled in a year: Similarweb

AI platforms sent an average of 770.7 million monthly visits to websites worldwide between June 2025 and May 2026, according to Similarweb’s worldwide traffic panel, more than double the prior year’s figure. The vendor’s September 2026 report breaks that total down by platform and by industry, and both breakdowns are lopsided: one chatbot sends most of the traffic, and three industries receive the most visits.

How much AI referral traffic?#

Similarweb’s panel puts total AI referral traffic at 770.7 million average monthly visits across the twelve months to May 2026, a 117.4% increase year over year. That total spans six platforms: ChatGPT, Gemini, Claude, Perplexity, Grok and DeepSeek. It is not evenly split. In a separate mid-2025 analysis of the top 1,000 global domains, the same panel found ChatGPT alone accounted for more than 80% of the AI referral traffic reaching those sites, with the other five platforms dividing what remained. Similarweb’s published report does not state a panel size or sampling method beyond describing it as worldwide web-traffic data, so the underlying domain count behind either figure is not disclosed on the report page itself.

Which industries receive the traffic#

Marketplaces topped every industry Similarweb tracked, at 46.8 million average monthly AI referral visits and 237.3% year-over-year growth. News and travel tied for second, each at 44.5 million monthly visits and 115.6% growth. Finance (19.1 million, up 236.5%) and consumer electronics (17.1 million, up 215.4%) followed, then fashion (5.6 million, up 278.2%) and beauty, the smallest tracked category at 2.0 million monthly visits despite the highest growth rate in the report at 312.5%.

The pattern across every industry in the report is the same shape: small absolute volumes next to triple-digit growth rates. A category can more than triple its AI referral traffic year over year and still receive a fraction of the visits a marketplace or a news site gets in raw terms, because the growth rate and the base it is growing from are two different numbers.

Why we care#

The volume is real, and it is a floor. 770.7 million monthly visits is large, and Similarweb notes that visits arriving without referrer data land in direct traffic, so referral counts understate AI’s real influence. Treat AI referral growth rates and organic search decline figures as two separate trend lines, not two measurements of the same shift.

One platform’s dominance changes what “optimizing for AI” actually means in practice. With ChatGPT sending more than 80% of AI referral traffic to top domains in mid-2025, a publisher deciding where to invest citation and structured-data effort is mostly deciding how to be cited by one product, not six. That concentration is worth checking again as Gemini and the other platforms report separately how their own referral share is moving.