AI Search Metric
AI-referred traffic
Also known as: AI traffic, LLM traffic
Sessions referred from ChatGPT, Claude, Gemini, Perplexity, Copilot, and other LLM surfaces. Often under-counted in standard analytics because referrers are stripped or labelled as direct.
What it is
AI-referred traffic is the set of sessions referred from LLM surfaces such as ChatGPT, Claude, Gemini, Perplexity, and Copilot. It is the measurable downstream of being cited or mentioned in AI answers.
Why it matters
It is the clearest proof that AI visibility converts to visits, but it is often under-counted because referrers are stripped or mislabelled as direct, so brands routinely undervalue this channel.
How it works
Practitioners identify AI referrers in analytics, build segments and rules to reclaim sessions hidden in direct traffic, and use UTM or server logs to attribute visits to specific assistants.
When it applies
Measure it whenever you need to tie AI-search effort to actual sessions and conversions.
Examples
- A spike in direct traffic that correlates with a rise in citation share
- Sessions arriving with a Perplexity or ChatGPT referrer string
- A team building an analytics segment to isolate assistant referrals
How it is measured
- Sessions with a recognised LLM referrer
- Estimated AI sessions reclaimed from direct traffic
- Conversions attributed to AI-referred sessions
- Share of total traffic from AI surfaces over time
Related terms in AI Search Metric
- Answer attribution rateThe proportion of AI answers that explicitly link back to source pages versus those that summarise without attribution. Attribution rate varies materially by platform and query type.
- Bounce-back rate (AI surface)The rate at which users return to the SERP or refine the prompt after seeing an AI Overview. Google's internal signal that an Overview failed, high bounce-back is associated with Overviews being silently removed for that query cluster.
- Brand mention rateThe frequency at which an LLM mentions a brand by name in answers across a prompt set, with or without citation. Brand mentions without citation are an early indicator of model-internalised brand awareness.
- Citation depthHow early in an AI-generated answer a source is cited. Earlier citations correlate with higher click-through from AI surfaces and stronger user trust signals.
- Citation diversity indexThe number of distinct domains an LLM cites across a prompt set, normalised by prompt count. Falling diversity in a category signals consolidation, and a closing window for new entrants.
- Citation shareThe proportion of times a domain or page is cited inside AI-generated answers (ChatGPT, Claude, Gemini, Perplexity, AI Overviews) across a tracked prompt set. The AI-era equivalent of share-of-voice and the metric most predictive of branded discovery in 2026.