What does ChatGPT traffic look like in GA4?
Two forms, both ChatGPT: the source is chatgpt.com, and the medium may be referral or ai-assistant. There are two reasons.
- OpenAI’s Help Center says ChatGPT search automatically adds utm_source=chatgpt.com to links, so sites can see ChatGPT search visits in tools like Google Analytics.
- Google Analytics’ default channel group has an AI Assistant channel: a session is labeled ai-assistant when the medium is ai-assistant or the referrer is on its list of AI assistants. Google’s examples are ChatGPT, Gemini, Deepseek, Copilot and Grok; the full list is not published.
This channel does not include Google’s own AI Overviews and AI Mode; the official description says they are excluded.
A real example: seven days of MochiStamp sources
MochiStamp is a site we publish as a case (with its operator’s consent). In its GA4, sessions for 2026-10-28 to 2026-11-03 by source / medium look like this (all rows add up to 140 sessions; the table shows five of them):
| Source / medium | Sessions |
|---|---|
| google / organic | 46 |
| (direct) / (none) | 42 |
| chatgpt.com / ai-assistant | 39 |
| openai / organic | 5 |
| bing / organic | 2 |
chatgpt.com brought 39 sessions, about 28%, the same order of magnitude as google / organic’s 46 and far more than Bing. The medium column reads ai-assistant, which matches Google’s description of the AI Assistant channel above; we did not check this property’s channel settings, so we do not conclude it must come from the default channel group.
Another 5 sessions have the source openai (medium organic). We have not verified where that source comes from, so we log it as its own row and do not count it as chatgpt.com.
The sample is small: seven days, one site, a bit over a hundred sessions. One thing it does show: looking only at google / organic and direct would miss a source already about as big as search. For comparison, another site: in GammaSlide’s two weeks of sessions from 2026-10-12 to 10-25, AI products (chatgpt.com, perplexity.ai, claude.ai) had 0 sessions and direct had 144. Two sites over two periods cannot be ranked against each other.
How do you find it in GA4?
1. Check for the built-in AI Assistant channel
Open Reports > Acquisition > Traffic acquisition, set the table dimension to Session default channel group, and look for an AI Assistant row. If it is there, you can read the channel’s sessions directly; if not, there may be no such visits yet, or your sources may not be on Google’s list. Continue to step 2.
2. Then look by source / medium
Switch the dimension to Session source / medium and type chatgpt or openai in the search box above the table to see which rows exist. That is how MochiStamp’s chatgpt.com / ai-assistant row was found.
3. Build your own channel group as a backstop
The default list is not fully published and may miss tools you care about. Go to Admin > Data display > Channel groups, copy the default channel group, add a channel called AI products, choose the condition Session source, matches regex, and enter:
chatgpt\.com|chat\.openai\.com|perplexity\.ai|claude\.ai|gemini\.google\.com|copilot\.microsoft\.com
Place this channel above Referral (rules match in order, first match wins) and save. These domains are common entry points, not an official list; add others based on the sources you see in step 2. A new channel group classifies data from the time it is created, so use the step 2 search for history.
4. Break it down by landing page
In Traffic acquisition add Landing page as a second dimension and filter by the sources above. See which pages ChatGPT sends people to: the homepage, or a particular guide. The pages sent most are the ones AI is citing, so make them clearer first.
5. Record a baseline every week
On the same day each week, note three numbers: sessions from AI products, the top three landing pages among them, and sign-up or purchase events from this channel. Small numbers jump around, so look at the direction over several weeks, not one week.
Which AI visits can GA4 not see?
GA4 can only recognize visits that carry source information. If a user opens a link from ChatGPT or another app without a source, the visit falls into Direct, which is one reason Direct is often the biggest row. If someone sees your name in an AI answer, does not click, then searches for you or types your URL, that is not recorded as an AI source either.
So AI-source sessions are a lower bound, not a total. To know whether AI answers mention you at all, ask your buyers’ questions yourself, as described in the AI visibility audit checklist; to confirm AI crawlers can get in first, use the AI crawler check.
FAQ
What is the source of ChatGPT traffic in GA4?
OpenAI’s Help Center says ChatGPT search adds utm_source=chatgpt.com to links, so the source is normally chatgpt.com. The medium may be referral, or GA4 may label it ai-assistant.
Does GA4 have a dedicated AI channel?
Yes. The default channel group has AI Assistant, with the medium ai-assistant. The list is not fully published, so also build your own channel group that matches sources by regex as a backstop.
Do clicks from Google’s AI Overviews and AI Mode count as AI Assistant?
No. Google’s description says this channel excludes AI Overviews and AI Mode; their clicks count as Google Search.
Why is my ChatGPT traffic zero or very low?
There may really be none, or the visits may have been recorded as Direct: GA4 cannot recognize visits without source information. Search chatgpt and openai in Session source / medium, then ask your buyers’ questions a few times and see whether ChatGPT’s answers include you.
Is it worth watching with only a few sessions a day?
Yes, once a week. Small numbers jump around, so the direction over several weeks and the landing pages are more useful than a single day’s number.
Sources
- Google Analytics · Default channel group （checked 2026-11-04）
- OpenAI · Publishers and Developers FAQ （checked 2026-11-04）
- MochiStamp · GA4 sessions by source, 2026-10-28 – 2026-11-03 （Operator’s GA4, exported 2026-11-04）
- GammaSlide · GA4 sessions by source, 2026-10-12 – 2026-10-25 （Operator’s GA4, exported 2026-10-27）
- kagentx evaluations: the data on the case study pages; each example gives its date.