AI Referral
An AI referral is a visit whose Referer names a known AI assistant or AI search product; stripped headers make the observed count a floor.
An AI referral is a visit that arrives with a Referer header naming a known AI assistant or AI search product. It is the observable visitor side of AI traffic measurement.
How it is detected
When a visitor follows a link from an AI product, the destination site inspects the arriving request’s Referer. If it names a known AI platform, the visit is counted as an AI referral and attributed to that platform.
Search-engine results pages are excluded by definition. Some operators use one crawler for both search and AI, but their search referrals are outside this measurement and their shared crawls cannot be attributed to either side.
The limit that matters
AI platforms frequently strip the Referer header. Those visits leave no platform name for the destination site to detect, so the observed referral count is a floor, not a total. Zero detected AI referrals does not show that AI products never linked to the site.
This undercount also affects the crawl-to-referral ratio: because referrals form its denominator, the resulting N:1 ratio is an upper bound rather than a precise measurement.
An AI referral shows that a person arrived through a link from an AI product. It does not reveal the model’s answer, whether the answer cited the site, or whether a prior crawler fetch caused the visit. That distinction also limits what generative engine optimization can be measured from site logs.
Related terms
- Crawl-to-Referral Ratio, pages fetched per detected visitor returned
- Generative Engine Optimization, the practice surrounding AI discoverability and use
- AI Traffic Exchange report, a fixed-window example of crawls and referrals
Frequently Asked Questions
How is an AI referral detected? +
The arriving request must carry a Referer header naming a known AI assistant or AI search product. The platform named by that header is recorded as the source of the visit.
Does the AI referral count include every AI-sent visit? +
No. AI platforms frequently strip the Referer header, leaving those arrivals indistinguishable in site logs. The detected count is therefore a floor, not a total, and zero recorded referrals does not prove that no AI product linked to the site.
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