In Google Analytics 4 you'll find these visits in the Traffic acquisition report under the AI Assistant channel. Since May 13, 2026, Google automatically sets the medium ai-assistant and the campaign name (ai-assistant) when the referrer belongs to a recognized AI assistant. ChatGPT also appends utm_source=chatgpt.com to the links in its answers. Clicks from Google AI Overviews and AI Mode, on the other hand, don't land in this channel but in Organic Search.
- The "AI Assistant" channel is part of the default channel group and needs no setup (Google Analytics, what's new).
- Google names ChatGPT, Gemini, Deepseek, Copilot and Grok as examples. Perplexity is not on that list: check the session source yourself.
- A custom channel group with a regex also catches what the default misses, and it applies retroactively.
- ChatGPT links carry
utm_source=chatgpt.com, confirmed by OpenAI. - Your numbers are a lower bound, not the truth: missing referrers, consent, ad blockers.
- Analytics shows clicks, not mentions. If an AI names you and nobody clicks, it stays invisible.
The fastest way: the "AI Assistant" channel
Four steps, no configuration:
- In GA4, open Acquisition → Traffic acquisition.
- Set the primary dimension to Session default channel group.
- Find the AI Assistant row. It contains the visits whose referrer belongs to a recognized assistant.
- Add Session source as a secondary dimension. Only there can you see whether
chatgpt.com,perplexity.aior something else sits behind the row.
Step 4 is the important one. The channel description in Google's documentation on the default channel group names ChatGPT, Gemini, Deepseek, Copilot and Grok as examples; Google doesn't publish the full list of recognized assistants. Perplexity isn't in that list, but it does appear in the new source group dimension, which Google has been rolling out since June 11, 2026 and which lists ChatGPT (OpenAI) and Perplexity as separate groups. So don't assume both assistants land in the same channel. Check.
How to recognize each source
| Origin | What you see in GA4 | In practice |
|---|---|---|
| ChatGPT (web) | Session source chatgpt.com, medium ai-assistant, campaign (ai-assistant) | The parameter utm_source=chatgpt.com also appears in the landing page URL |
| Perplexity | Session source contains perplexity | Included in Google's regex example for AI assistants but not named in the channel description: cover it with a custom channel group |
| Google AI Overviews, AI Mode | google / organic, channel Organic Search | According to Google explicitly not part of the AI Assistant channel; there is no way to separate them from classic search |
| AI app without a referrer | (direct) / (none) | Only shows up if a UTM parameter survives, otherwise impossible to attribute |
OpenAI states that ChatGPT sets the UTM parameter itself in its FAQ for publishers and developers: if you give OAI-SearchBot access, you can use it to track referral traffic from ChatGPT in analytics platforms.
A custom channel group: when you need more precision
For agencies, and for anyone who wants to compare trends cleanly over months, a custom channel group is the more robust route. Google itself describes this case as the "AI assistants" example in its help on custom channel groups:
- Open Admin → Data display → Channel groups and create a new group as a copy of the default group. You need at least the Editor role at property level.
- Create a channel, for example "AI assistants", with the condition matches regex.
- Enter this expression, taken from Google's example:
^.*ai|.*\.openai.*|.*chatgpt.*|.*gemini.*|.*gpt.*|.*copilot.*|.*perplexity.*|.*google.*bard.*|.*bard.*google.*|.*bard.*|.*.*gemini.*google.*$ - Reorder the channels so the new one sits above "Referral". A visit lands in the first channel whose definition it matches.
- Save the group and select it as the primary or secondary dimension in User acquisition or Traffic acquisition.
Three things that will save you trouble later: custom channel groups apply retroactively, so you see your history right away. Standard properties allow 2 groups in addition to the predefined one, with 50 channels each. And they aren't available in the BigQuery export. If you analyze there, keep filtering by source and medium.
The regex is broad. ^.*ai matches every source that starts with "ai", and .*gpt.* also matches domains that have nothing to do with an assistant. After two weeks, look at the session sources in your new channel and trim the expression down to the domains that actually occur for you. Google itself points out that you need to maintain the expression as new assistants appear.
Why your numbers are too low
Every one of these numbers is a lower bound. In its help on "(direct) / (none)", Google lists the reasons: missing UTM parameters, redirects and short URLs that strip parameters along the way, plus ad blockers that interfere with tracking.
In Germany, consent comes on top. Under Section 25(1) TDDDG, the German law on data protection in telecommunications and digital services, storing information on a user's device or accessing it is only permitted if the user has consented on the basis of clear and comprehensive information. Analytics cookies generally fall under this unless an exception under Section 25(2) TDDDG applies. Storing or accessing without consent is an administrative offence under Section 28(1) No. 13 TDDDG, with fines of up to 300,000 euros. In practice, this means your AI Assistant channel only shows sessions with consent. Read it as a trend, not as a visitor count.
What Google Analytics doesn't show
The blind spot is bigger than the measurement gap. Analytics counts clicks. Whether ChatGPT names your brand in an answer without anyone tapping the link isn't recorded there, and in our experience that happens often with AI answers. Referral traffic proves the business value of your visibility; it doesn't measure it.
For mentions you need a second measurement: ask the same real questions from your audience across several answer engines on a regular schedule, and record whether you were mentioned, cited or absent. We describe how to measure your visibility in AI answers in a separate article. flize brings exactly this cycle of scouting, Answer Check, content production and attribution together in one place.
Why do I sometimes see ChatGPT traffic under "Direct"?
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Because the referrer is missing and no parameter survived. That happens with clicks from apps, with redirects and with short URLs. First check whether your redirects pass query parameters along: that is the most common self-inflicted gap.
Can I see which question someone asked ChatGPT?
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No. Google's overview of traffic source dimensions lists source, medium, campaign, campaign ID, source platform and default channel group; there is no dimension for the prompt. You see the source and the landing page. The landing page is the best proxy: it tells you which of your answers was cited.
Are clicks from Google AI Overviews included?
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No. Google explicitly assigns AI Overviews and AI Mode to Organic Search and excludes them from the AI Assistant channel. In GA4 they therefore can't be separated from classic Google search.
Do I need an extra tool for this?
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Not for the clicks; GA4 is enough. For the question of which answers you appear in at all, it isn't, because many mentions end without a click.
