The short answer
Start with GA4’s AI Assistant channel, which Google added in May 2026 for referrals from assistants such as ChatGPT and Gemini. Google does not publish the full list, so add a custom channel group for sources it may miss, such as Perplexity. Then remember the limit: analytics only sees clicks. An answer that recommends you without a click never reaches your reports.
Someone asks ChatGPT which tool to use, gets your name and a link, and clicks. Lovely. Now open your analytics and try to find that person. Depending on the assistant, the app and the browser, they may be under AI Assistant, Referral, or Direct, looking exactly like someone who typed your URL from memory.
This guide sets up the reporting you can trust, then marks the part no tracking setup will ever show.
GA4 now has an AI Assistant channel
On 13 May 2026, Google announced a new AI Assistant channel in the default channel group, so you can see visits from chatbots “like ChatGPT, Gemini, and Claude”. The channel definition says GA4 sets the medium to ai-assistant when the referrer matches its list of AI assistants. The examples there are ChatGPT, Gemini, DeepSeek, Copilot and Grok.
Two caveats. First, Google calls these examples and does not publish the full list, so you cannot be sure which smaller assistants are included. Perplexity, for instance, is not named on either page. Second, a channel only classifies visits that arrive with a recognisable referrer. Some reports say the channel took weeks to fill in for many properties after launch; we have not verified that independently, but it is a reason not to compare April with June directly.
Where to look: Reports, Acquisition, Traffic acquisition, with the primary dimension set to Session default channel group. Then switch to Session source to see which assistants are actually sending visits.
ChatGPT tags its search links. Others are less predictable
OpenAI’s publisher FAQ says ChatGPT automatically adds utm_source=chatgpt.com to referral URLs from ChatGPT search results. That is the most reliable signal you will get, and it survives cases where the referrer header does not. Note the scope: OpenAI describes search results, not every link in every conversation.
We could not find equivalent official documentation for Perplexity, Claude, Gemini or Copilot. In practice, people commonly report seeing them as referrals from perplexity.ai, claude.ai, gemini.google.com and copilot.microsoft.com. Treat that as observed behaviour that can change, not a promise.
Why some visits arrive as Direct: browsers send only the origin of the linking site by default under the strict-origin-when-cross-origin policy, and links opened from native apps or in-app browsers often arrive with no referrer at all. Without a referrer or a surviving UTM, analytics has nothing to classify. This is an inference from how browsers and apps work; OpenAI has not published how its apps handle referrers.
Build a custom channel group for the gaps
You cannot edit GA4’s default channel group, but you can create a custom one. It starts as a copy of the default, applies to past data, and needs the Editor role. Standard properties get two custom groups.
- Go to Admin, Data display, Channel groups, and choose Create new channel group.
- Add a channel called AI assistants with the condition: Source matches regex, using the pattern below.
- Move it above Referral. GA4 assigns each session to the first channel that matches, so order matters.
- Save, then compare the new group with the default one for the last 90 days. If the numbers are wildly different, look at the sources before trusting either.
Google’s own help page includes an AI example, but its sample pattern is broad enough to catch unrelated sources. Whatever pattern you use, write it down with the date. When an assistant changes domain, the pattern needs updating, and Google says so too.
The part no analytics tool can see
Here is the uncomfortable bit. Most AI answers do not produce a click. A buyer can read a recommendation, remember your name and search for it a week later. That visit shows up as branded search or Direct. And when an assistant recommends a competitor instead, nothing shows up anywhere.
Search engines now report some of this. Search Console’s generative AI performance report, rolled out to all sites by 31 August 2026, shows impressions in AI Overviews and AI Mode combined. Its help page describes impressions only, with no click data. Bing Webmaster Tools reports citations in Copilot and Bing answers, and Microsoft calls its Citation Share figure observational, not a ranking. Neither covers ChatGPT, Claude or Perplexity.
For those, the only way to know what buyers are told is to ask the questions yourself and keep the answers. Our free baseline guide shows how to do it with a spreadsheet.
What to put in the monthly report
| Measure | Where it comes from | What it can’t tell you |
|---|---|---|
| AI assistant sessions and conversions | GA4, default and custom channel groups | Visits without a referrer or UTM, and every answer that produced no click. |
| AI-feature impressions and citations | Search Console and Bing Webmaster Tools | ChatGPT, Claude and Perplexity; and whether the answer recommended you. |
| Mentions and recommendations for buying questions | Repeated checks of real questions, with saved answers | Traffic or revenue. It shows what buyers are told, not what they do next. |
Keep them side by side, and resist adding them up. For scale: SE Ranking’s study of about 100,000 sites put AI platforms at roughly 0.3% of all website traffic in its sample. Small in sessions, but these are often people already deep in a buying question. Our KPI guide shows how to report this without inventing attribution.
Sources & context
Examples and figures are illustrative unless explicitly stated otherwise. Written and published by Share of Voice, a Superstellar LLC product. We sell AI visibility reports; our commercial perspective is worth keeping in mind.
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