Methodology
How we measure traffic from AI assistants
Every AI traffic figure in CitePatch comes from the definition on this page. We publish it because a number you cannot audit is a number you cannot take to your board, and because the honest version of this measurement has limits that a rounded figure hides.
- Definition in force
citepatch_definition_v1- In effect since
- 1 January 2025
The definition is a CitePatch constant, identical for every customer and never configurable per project. If each account defined AI traffic for itself the figures would stop being comparable and this page would stop meaning anything.
The surfaces we recognise
A session counts as AI referral traffic when the referrer identifies one of these assistants. The list is a versioned decision, not a law of nature.
| Surface | Identified by | Visible in analytics sessions |
|---|---|---|
| ChatGPT | chatgpt.com, chat.openai.com | Yes |
| Perplexity | perplexity.ai | Yes |
| Gemini | gemini.google.com, bard.google.com | Yes |
| Claude | claude.ai, anthropic.com | Yes |
| Microsoft Copilot | copilot.microsoft.com | Yes |
| Other assistant | Tagged by Google as an assistant, with a referrer we cannot name | Yes |
| Google AI Overviews | No distinct referrer — the click looks like organic search | No |
| Google AI Mode | No distinct referrer — the click looks like organic search | No |
Clicks from AI Overviews and AI Mode arrive with a google.com referrer that is indistinguishable from an ordinary organic result, so they cannot be separated in analytics session data at all. They are not silently folded into the AI traffic figure; where they are reported, the source is Search Console's generative-AI report and it is labelled as such.
Two methods, one figure
Google added a native AI Assistant channel to Analytics, but only recently, so a series that covers a year was classified two different ways. Rather than pick one and quietly apply it to everything, each range carries the method that produced it.
- ga4_native_channel — the session was tagged by Google's own AI Assistant channel.
- citepatch_definition_v1 — the session was matched against the referrer patterns in the table above.
- A session Google tagged as an assistant but whose referrer we cannot name is still counted, as Other assistant. Discarding it would understate the floor; an absent referrer, by contrast, is not evidence of origin.
13 May 2026 is a change of method, not a change of traffic
Google began rolling out the native AI Assistant channel on 13 May 2026 and had reached most properties by 1 June 2026. It is a rollout window rather than a clean cut, and a step in the chart around those dates is very likely the measurement changing rather than the traffic.
- Any series that crosses the window is annotated in the product, so nobody reads the step as a result.
- We treat it as a window, not a date, because properties switched over at different moments and pretending otherwise would put a false precision on the boundary.
The figure is a floor, never a total
Between 20% and 40% of assistant sessions arrive with the referrer stripped and land in Direct, where they can be neither confirmed nor denied. This is the single most important thing to understand about the number.
- We report the identified sessions and the unattributable remainder side by side, and we never add them together.
- Read every figure as at least N sessions from this assistant, not as the total.
- Only (direct) / (none) counts towards the unattributable remainder. A session with a known non-AI referrer is not an unknown, and is not quietly moved into the maybe pile.
What this definition cannot see
The limits are part of the method. A tool that reports AI traffic without stating these is not measuring more than we are; it is telling you less about what it measured.
- AI Overviews and AI Mode, for the reason in the table above.
- Assistants that strip the referrer, and browsers or privacy tooling that strip it for them.
- A conversation that happens in an app and ends in a browser the user opens themselves, which arrives as Direct like any other typed URL.
- Assistants Google recognises but does not name: its internal list is not public and changes without notice.
- Any assistant that is not in the table. The list is our decision, it can fall short, and when it does the figure is low rather than wrong.
How this changes
A definition that can be revised without notice is not auditable, so revisions are versioned in the open.
- A new version gets a new identifier and its own effective date.
- Ranges already classified keep the label they were classified with; we do not restate history under a new method.
- The version that produced a figure travels with the figure, in the product and in exports.
When will I see results?
Every AI answer is one of two different things, and each runs on its own clock. An assistant that searches the web first — ChatGPT with search on, Perplexity, Gemini, Copilot, Google's AI Overviews — reads whatever is indexed at the moment of the question and cites it, so a change to a page can show up in an answer once that surface has re-crawled and re-indexed it. An assistant answering from memory did not search at all: it is repeating what it learned during training, and that only changes when the model itself is retrained, a decision that belongs to the model's maker and to no one else. A single promised date treats the first case as if it covered both, and that is a promise we will not make.
- Search-grounded answers move with the index, not the model — the pace is set by re-crawl and reindexing, which belongs to Google and the other engines, not to us.
- Memory-based answers move only on retraining, and only the model's maker decides when that happens.
- So instead of a date, we name the exact question you are losing, show the evidence for why, propose the change, and apply it through your own stack once you approve it.
- Afterward we keep asking the engines and tell you the day the page was actually re-crawled — the same discipline this whole page holds every other figure to: report what happened, not what should happen.