AI platforms are becoming a more visible source of website traffic, but they are still far from replacing Google Search as the main referral engine for major sites. New data from Similarweb shows a fast-growing channel that publishers, retailers, social platforms, and information sites can no longer ignore.
In June, AI platforms generated over 1.13 billion referrals to the top 1,000 websites globally. That was a 357% increase since June 2024. The same data also makes the scale gap clear: Google Search accounted for 191 billion referrals to those sites during June 2025.
AI referrals are rising from a smaller base
Similarweb defines AI referrals as web referrals to a domain from AI platforms such as ChatGPT, Gemini, DeepSeek, Grok, Perplexity, Claude, and Liner. By that measure, AI-driven discovery is already producing meaningful traffic for large sites, even if it remains much smaller than search.
ChatGPT is the dominant source within this AI referral category. Similarweb found that ChatGPT accounted for more than 80% of AI referrals to the top 1,000 domains.
The analysis excluded the OpenAI website because many of its referrals were from ChatGPT and pointed to OpenAI services. That exclusion matters because it keeps the ranking from being skewed by traffic moving inside the same broader ecosystem.
The broader picture is straightforward: AI platforms are sending more users out to the web than they did a year earlier, but Google Search remains the overwhelming traffic source for the largest websites. The change is not yet a replacement story. It is a redistribution story that is still developing.
News and media saw the sharpest concern
News and media is one of the most closely watched categories because publishers are already dealing with traffic pressure. Some online publishers are preparing for a possible future they call "Google Zero," a scenario in which Google stops sending traffic to websites.
Similarweb found that AI referrals to news and media websites in June were up 770% since June 2024. That is a faster increase than the overall AI referral growth measured across the top 1,000 websites globally.
But the news category also shows how uneven the new traffic environment may become. Some sites can rank higher in AI-driven referrals, while others may block access to AI platforms. The New York Times is cited as an example of a site blocking access, in connection with its lawsuit with OpenAI over the use of its articles to train models.
In the news media category, Yahoo led with 2.3 million AI referrals in June 2025. Yahoo Japan followed with 1.9M, Reuters had 1.8M, The Guardian had 1.7M, India Times had 1.2M, and Business Insider had 1.0M.
AI summaries are changing click behavior
The pressure on publishers is not only about referrals from AI platforms. It is also about what happens inside Google Search when AI summaries appear.
The Wall Street Journal recently reported on data showing how AI overviews were affecting traffic to news sites. A Pew Research Center study out this week also found that, in a survey of 900 U.S. Google users, 18% of some 69,000 searches showed AI Overviews.
According to that Pew Research Center study, when AI Overviews appeared, users clicked links 8% of the time. When there was no AI summary, users clicked links nearly twice as much, or 15% of the time.
For publishers, that creates a difficult mix. AI platforms are sending more referral traffic than before, but AI-generated summaries in search can also reduce the need for users to click through. Both patterns can exist at the same time, which is why the overall effect is more complicated than a simple gain or loss.
Traffic gains vary widely by category
Similarweb also looked beyond news and media, including e-commerce, science and education, tech/search/social media, arts and entertainment, business, and other categories. The rankings show that AI referrals are not concentrated in one type of website.
In e-commerce, Amazon received 4.5M AI referrals in June. Etsy followed with 2.0M, and eBay had 1.8M.
Among top tech and social sites, Google led with 53.1 million AI referrals in June. Reddit followed with 11.1M, Facebook had 11.0M, Github had 7.4M, Microsoft had 5.1M, Canva had 5.0M, Instagram had 4.7M, LinkedIn had 4.4M, Bing had 3.1M, and Pinterest had 2.5M.
Across other categories, the top site by AI referrals included YouTube with 31.2M, Research Gate with 3.6M, Zillow with 776.2K, Europa.eu with 992.9K, Wikipedia with 10.8M, NIH.gov with 5.2M, Investing.com with 1.2M, Home Depot with 1.2M, Kayak with 456.5K, and Zara with 325.6K.
What the numbers show now
The current data points to a web traffic system in transition. AI referrals are growing quickly, and some categories, especially news and media, are seeing a steep year-over-year increase. At the same time, Google Search still sends far more traffic to the top websites than AI platforms do.
That means the practical question for website operators is not whether AI referrals matter. The data shows they already do. The harder question is how much they can offset shifts elsewhere, especially if AI summaries reduce clicks from traditional search results.
For now, the main takeaway is one of scale and direction. AI platforms are becoming a larger route to the web, led heavily by ChatGPT. But the center of gravity for referrals to major websites remains Google Search, at least in the June 2025 data Similarweb analyzed.