AI Referral Traffic Statistics: How Much ChatGPT, Perplexity and Gemini Send, and How It Converts

AI assistants now send websites hundreds of millions of visits a month, but on a typical site that is still under 4% of what Google organic delivers. Those visitors usually convert somewhat better than organic search, not 7x or 23x better, and GA4 misses a large share of them. Below are 30 numbered statistics on volume, growth, conversion and attribution, each with a named source and link. All sources were read on 29 October 2026.

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What are the key takeaways?

• Volume is real but small per site. AI platforms drove 770.7 million referral visits a month worldwide from June 2025 to May 2026, up 117.4% year over year (Similarweb). On 95 GA4 properties, AI sent 2.6% of the sessions organic search sent (The SEO Works).
• ChatGPT still dominates, but its share is slipping. ChatGPT accounted for 79.74% of AI referral traffic in 2025 and 75.96% in 2026 in SE Ranking's 101,574-site dataset.
• One product change moved the whole channel. After ChatGPT made brand names clickable around 7 May 2026, its referrals rose 157.7% week over week and homepage referrals rose 354.7% (Similarweb).
• The conversion edge is modest in multi-site data. Median AI-to-organic conversion ratios are 1.21x across 63 sites (The SEO Works) and 1.26x across 78 sites (Siege Media). B2B product sites converted worse, at 0.62x.
• GA4 undercounts AI. About 22% of ChatGPT sessions and 32% of Perplexity sessions landed in the "(not set)" medium across 181.6 million sessions (Workshop Digital).
• Organic still wins on total conversions. For every 100 organic conversions, AI referrals delivered 3.2 (The SEO Works).

How much traffic does ChatGPT send to websites?

ChatGPT is the largest AI referrer by a wide margin, but per site it sends very little. Across 100 sites and 145 million sessions, ChatGPT drove sessions equal to 0.62% of Google organic. Globally, ChatGPT accounted for about 76% of AI referral traffic in 2026, down from about 80% in 2025.

1. ChatGPT sent 0.62% as many sessions as Google organic. Marie Haynes analysed 12 months of GA4 data from 100 websites and more than 145 million sessions. Adding other LLMs raised the figure to 0.73% of Google organic traffic, not of total traffic. Source: Search Engine Land, 21 October 2026.
2. ChatGPT held 75.96% of all AI referral traffic in 2026, down from 79.74% in 2025. In the US its share fell from 75.78% to 72.41%; in the EU from 83.03% to 76.77%. Source: SE Ranking, 101,574 websites, 9 July 2026.
3. ChatGPT's referral share jumped 36.7% in one month. SE Ranking measured ChatGPT's worldwide referral share at 0.23% in April 2026 and 0.32% in May 2026, above the previous peak of 0.29% in October 2025. Source: SE Ranking.
4. ChatGPT accounted for more than 80% of AI referrals to the top 1,000 global domains in Similarweb's mid-2025 analysis. Source: Similarweb, 3 September 2026.
5. OpenAI crawled about 1,091 pages for every visit it referred in July 2025. Anthropic's ratio was 38,065 to 1 and Perplexity's 194.8 to 1, per Cloudflare Radar data. Source: Cloudflare, 29 August 2025.

The short answer for a single business: expect ChatGPT referrals well under 1% of organic sessions today, with step changes when OpenAI changes how links appear.

What share of website traffic comes from AI assistants?

AI assistants send a low single-digit share of most sites' traffic. Multi-site GA4 studies put AI referrals between 0.3% and 4% of organic sessions, and between 0.2% and 3% of total sessions. The figure depends heavily on the denominator, so always check whether a study divides by organic or by all traffic.

6. Organic search delivered 39 times more sessions than AI assistants across 95 websites from September 2025 to August 2026 (2,825,594 vs 72,095). AI equalled 2.6% of organic sessions. Source: The SEO Works benchmark, dataset on Zenodo, 29 September 2026.
7. AI referrals reached 3.86% of organic sessions in August 2026, up from 2.25% in September 2025, with the rise starting in May 2026. Source: The SEO Works.
8. AI made up 0.2% to 3% of total sessions on most sites in Siege Media's 78-site GA4 study (January to May 2026). Source: Siege Media, 30 June 2026.
9. Known AI sources peaked at 1.1% of organic traffic in July 2025, then settled at about 0.3% to 0.4%, across 22 clients and 181.6 million sessions. Source: Workshop Digital, 4 February 2026.
10. AI referrals were under 1% of overall traffic across more than 1,200 publisher and news sites. Source: Microsoft Clarity, 6 November 2025.
11. 0.5% of Ahrefs' traffic came from AI search in the 30 days studied (0.3% year to date), mostly from ChatGPT. Source: Ahrefs, June 2025.

Study	Sites	Period	AI share	Denominator
The SEO Works	95	Sep 2025 to Aug 2026	2.6% (3.86% in Aug 2026)	Organic sessions
Marie Haynes (via SEL)	100	12 months	0.73% (ChatGPT 0.62%)	Google organic sessions
Workshop Digital	22	2025	0.3% to 0.4% (peak 1.1%)	Organic sessions
Siege Media	78	Jan to May 2026	0.2% to 3%	Total sessions
Microsoft Clarity	1,200+ publishers	8 months	Under 1%	Total traffic
Ahrefs (own site)	1	30 days, 2025	0.5%	Total traffic

How fast is AI referral traffic growing?

Fast, from a small base, and in steps rather than a smooth curve. Similarweb measured 117.4% year-over-year growth in AI referral visits, and every industry it tracked at least doubled. Inside individual site samples, growth stalled in late 2025, then jumped in May 2026 when ChatGPT made brand names clickable.

12. AI platforms drove an average of 770.7 million referral visits a month worldwide between June 2025 and May 2026, up 117.4% year over year. Source: Similarweb, 3 September 2026.
13. Marketplaces led on volume at 46.8 million AI referral visits a month (+237.3%); News and Travel followed at 44.5 million each (+115.6%). Beauty grew fastest at +312.5%, Fashion +278.2%. Source: Similarweb.
14. ChatGPT referrals rose 157.7% week over week after 7 May 2026, and homepage referrals rose 354.7%. The homepage share of ChatGPT referrals moved from about 26% to 32% to about 60%. Source: Similarweb, desktop panel, 30 April to 20 May 2026.
15. AI referral volume rose 18% to 39% across customer segments after May 2026 (B2C +39%, B2B Services +36%, B2B Products +18%). Source: The SEO Works.
16. Generative AI traffic to US retail sites rose 693.4% year over year in the November to December 2025 holiday season. Travel rose 539%, financial services 266%, tech and software 120%. Source: Adobe Digital Insights, 12 January 2026.
17. AI traffic to 1,200+ publisher sites grew 155.6% over eight months, against 24.0% for search. Source: Microsoft Clarity.
18. ChatGPT referral growth stalled in August 2025 across Marie Haynes' 100-site sample. Source: Search Engine Land.

The growth figures that look contradictory are measuring different things. Panel data (Similarweb, Adobe) counts the whole web, where new users and new link formats compound. Single-portfolio GA4 data shows what a given set of businesses received, which flattened through late 2025.

Does AI referral traffic convert better than organic search?

Usually yes, by 18% to 26% in multi-site studies, and not everywhere. The SEO Works found AI sessions converted at 1.18x organic across 63 sites, and Siege Media found a 1.26x median across 78. Single-site case studies report 2.5x to 23x, which is why the headline numbers you see vary so much.

19. AI referrals converted at 7.18% vs 6.08% for organic (1.18x pooled, 1.21x median) across 63 websites with enough volume. AI converted worse than organic on 23 of them, and five recorded no AI conversions despite 1,487 AI sessions. Source: The SEO Works.
20. The multiple depends on the comparison channel. The same dataset gives 0.67x against paid search, 1.18x against organic, 1.37x against total sessions and 2.48x against direct. Source: The SEO Works.
21. Median AI-to-organic conversion ratio: 1.26x across 78 sites. AI matched or beat traditional traffic on 72% of sites. Finance led at 1.67x; B2B SaaS was 1.05x; e-commerce 1.01x. Source: Siege Media.
22. ChatGPT visitors converted at 13.8% vs 3.02% for Google organic among 55 sites tracking conversions, yet Google organic drove 27 times as many conversions as all LLMs combined. Source: Search Engine Land on Marie Haynes' study.
23. AI referrals converted 31% better than other traffic sources on US retail sites in holiday 2025, with revenue per visit up 254% year over year. Source: Adobe.
24. On e-commerce, ChatGPT referrals converted above paid social but below every other traditional channel, across 973 websites and more than 50,000 ChatGPT-referred transactions. Source: Kaiser and Schulze, Marketing Science 45(4), 2026.
25. 0.5% of Ahrefs' visitors drove 12.1% of its signups, a 23x higher conversion rate than its organic search visitors. Source: Ahrefs.

Does AI traffic convert better for B2B and SaaS?

It depends on what you sell. Single-company SaaS cases show AI visitors converting 1.7x to 2.5x better on trial signup. The largest multi-site cut found B2B product companies were the exception: AI converted at 0.62x organic, and worse on six of ten sites. B2B services sat at 1.21x.

26. B2B Products converted at 0.62x organic; B2B Services 1.21x; B2C 1.51x; Mixed 1.46x. B2B product sites also received the highest AI share, 3.40% of organic. AI converted worse than organic on six of the ten B2B product sites. Source: The SEO Works.
27. One B2B SaaS site saw 8.79% trial signup from AI vs 3.54% from organic (2.48x) over 99,018 sessions, July 2025 to June 2026. AI was 2.6% of combined traffic and 6.3% of signups. Source: MySEOConsult, 22 July 2026.
28. At OtterlyAI, ChatGPT visitors converted to signup at 25% vs 15% for Google Search. Source: Otterly, updated 6 July 2026.

MySEOConsult attributes most of its gap to page mix: AI visitors landed on pricing, signup and feature pages, while organic visitors landed on informational posts. That points to a practical lesson: the pages AI assistants send people to matter as much as the channel. SE Ranking found 60% of AI-referred traffic lands on homepages, compared with 17% from organic search (SE Ranking).

Want to know which buyer questions put you in the answer, and what that traffic is worth? Start a 14-day trial, no card: five prompts, all six engines, GA4 attribution.

Why does GA4 undercount AI referral traffic?

GA4 can only label a session as AI when the assistant passes a referrer. Mobile apps, in-app browsers and copy-pasted links often strip it, so those visits land in direct or "(not set)". Google AI Overviews clicks arrive as ordinary organic sessions and cannot be separated at all. Every published AI traffic figure is therefore a floor.

29. About 22% of ChatGPT sessions and 32% of Perplexity sessions were filed under the "(not set)" medium, and 0.5% of ChatGPT traffic was classified as organic. Claude and Gemini sessions were attributed to referral 100% of the time. Source: Workshop Digital.
30. GA4 last-touch credited Claude with 0.1% of OtterlyAI's signups; a post-signup survey credited it with 10.6%. ChatGPT moved from 7% (GA4) to 11% (survey), and Google Search fell from 35% to 15.7%. Source: Otterly.

Two further measurement facts matter. GA4's own "AI Assistant" channel only exists from June 2026, so earlier history needs a referrer regex, per The SEO Works. And Loamly, which sells AI-traffic detection, found that 70.6% of the AI visits it identified (14,413 of 20,428 across 446,405 visits) arrived without a referrer (Loamly, updated 16 February 2026).

What to do with this:

• Build a custom channel group that matches chatgpt, openai, perplexity, claude, gemini, copilot and similar referrers, and watch the "(not set)" medium.
• Add a "how did you hear about us" field at signup. Otterly's gap between GA4 and the survey is the size of your blind spot.
• Report AI conversions next to AI citations. A page can be cited constantly and send almost no clicks.

Mentionova's AI traffic view reads AI-referred sessions from GA4 by platform and landing page, and its own documentation says to treat the result as a floor, for the same referrer reasons.

How should you read AI traffic statistics before acting on them?

Check four things: the denominator (organic, total or paid), the sample (one site or many), the comparison channel, and the date relative to May 2026. Most of the disagreement between "AI converts 23x better" and "1.18x" comes from those four choices, not from contradictory data.

• One site vs many. Ahrefs (23x), MySEOConsult (2.48x) and Otterly (1.67x) each measured their own funnel. The SEO Works and Siege Media pooled 63 to 78 sites and found about 1.2x.
• Comparison channel. The SEO Works' data ranges from 0.67x to 2.48x depending on whether AI is compared with paid search or direct.
• Volume. The SEO Works estimates a 5% lift in organic search would add 10.3 conversions per site per month, more than the 6.6 from doubling AI referrals.
• Vendor interest. Several sources sell AI visibility or analytics products, including Ahrefs, Similarweb, SE Ranking, Otterly, Loamly and Mentionova itself. That does not make their data wrong, but it is worth knowing.

The case for tracking AI visibility is not that the traffic is large. It is that buyers who arrive from an AI answer are often further along, and that AI mentions shape decisions that never show up as a referral. For the citation side of the picture, see LLM citation statistics. For how the AI answer itself shifts from run to run, see the six-engine divergence index.

Where does Mentionova fit, and where does it not?

Mentionova tracks whether ChatGPT, Perplexity, Claude, Gemini, Google AI and Reddit name and cite you for your buyer prompts, and connects GA4 to show the sessions those engines send. It runs weekly, fortnightly or monthly, not daily. Starter is $125 a month ($99 billed annually) for 25 prompts on three engines.

What that means in practice:

• It answers "are we in the answer, and which pages does AI traffic land on?" in one place. The AI visibility tracking page covers the product.
• It will not recover the referrer-stripped visits GA4 never sees. No analytics integration can.
• If you need daily snapshots or the cheapest possible tracker, other tools fit better; see AI visibility tool pricing. Full plan details are on the pricing page.

The 14-day trial needs no card and includes 5 prompts and all six engines.

Where does each number come from?

All sources read on 29 October 2026.

• Similarweb, AI referral traffic by industry (3 September 2026) and ChatGPT referral traffic after clickable brand links (May 2026 update), aisearch.similarweb.com.
• SE Ranking, ChatGPT referral traffic study (9 July 2026), 101,574 websites.
• The SEO Works, AI Referral Traffic Benchmark, 95 GA4 properties, September 2025 to August 2026; paper and data on Zenodo (doi 10.5281/zenodo.23040387, 29 September 2026).
• Siege Media, AI traffic conversion rates study (updated 30 June 2026), 78 sites.
• Search Engine Land, Danny Goodwin (21 October 2026), reporting Marie Haynes' 100-site analysis.
• Workshop Digital, AI referral gap study (4 February 2026), 181.6 million GA4 sessions.
• Microsoft Clarity publisher study (6 November 2025), 1,200+ sites.
• Adobe Digital Insights, holiday 2025 AI traffic (12 January 2026).
• Kaiser and Schulze, "ChatGPT Referrals to E-Commerce Websites", Marketing Science 45(4): 699 to 715 (2026).
• Ahrefs, Patrick Stox, AI search traffic and signups (June 2025).
• MySEOConsult, 12-month SaaS study (22 July 2026); Otterly, AI search conversion measurement (updated 6 July 2026).
• Cloudflare, crawl-to-refer ratios (29 August 2025); Loamly, AI traffic attribution (updated 16 February 2026), vendor data.
• Mentionova plan limits: mentionova.com/pricing.

What do people ask about AI referral traffic?

How much traffic does ChatGPT send to websites?

Across 100 sites and 145 million sessions, ChatGPT sent sessions equal to 0.62% of Google organic, per Marie Haynes' analysis as published by Search Engine Land. Worldwide, Similarweb counts 770.7 million AI referral visits a month, with ChatGPT the largest source.

Does AI referral traffic convert better than organic?

In multi-site studies, modestly: 1.18x pooled across 63 sites (The SEO Works) and a 1.26x median across 78 sites (Siege Media). AI converted worse than organic on 23 of the 63 sites, and B2B product companies averaged 0.62x.

Which AI platform sends the most referral traffic?

ChatGPT, with 75.96% of AI referral traffic in 2026 in SE Ranking's data, down from 79.74% in 2025. Gemini, Perplexity, Claude, Copilot and others make up the rest, and their combined share is growing.

Why did ChatGPT referral traffic jump in May 2026?

Around 7 May 2026 ChatGPT began showing brand names as clickable links. Similarweb measured a 157.7% week-over-week rise in ChatGPT referrals and a 354.7% rise in homepage referrals.

How do I track AI referral traffic in GA4?

Create a custom channel group matching AI referrers (chatgpt, openai, perplexity, claude, gemini, copilot) and watch the "(not set)" medium, where Workshop Digital found 22% of ChatGPT sessions. GA4 added an AI Assistant channel in June 2026.

Why does my AI traffic look lower than I expected?

Mobile apps and copy-pasted links often strip the referrer, so those visits show as direct. Google AI Overviews clicks count as organic. Otterly's GA4 credited Claude with 0.1% of signups while its survey credited 10.6%.

Is AI referral traffic worth optimizing for?

Treat it as a high-intent, low-volume channel. The SEO Works found AI delivered 3.2 conversions for every 100 from organic, but buyers increasingly start research in AI answers, and most of that influence is never recorded as a click.

See which AI answers name you, and what they send. Start the 14-day trial, no card.