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How to track AI traffic in GA4 (and what it can't see)

Is ChatGPT sending you anyone? Google Analytics 4 can answer part of that question. Not all of it. Here is how to set it up in about ten minutes, and where the number stops being true.

Step 0: check the channel GA4 already has

GA4's default channel group now includes an "AI Assistant" channel. Google describes it as visits "from sources like ChatGPT, Gemini, Deepseek, Copilot, or Grok." GA4 sets the medium to "ai-assistant" when the referrer matches its own list of AI assistants.

So before you build anything, open Reports, then Acquisition, then Traffic acquisition, and look for an AI Assistant row. If it's there, you already have a baseline.

Two things to know about that default channel:

  • Google's AI Overviews and AI Mode are not in it. Google counts those clicks under Organic Search.
  • You can't edit it. Google keeps the default channel group the same for everyone. If you want your own list of sources, you need a custom channel group.

Step 1: build a custom AI channel

A custom group is worth it if you want to control exactly which sources count as AI, or if you want to split them out. Google documents an "AI assistants" example in its own help pages. The steps:

  1. Go to Admin, then Data display, then Channel groups. You need Editor access or above.
  2. Click "Create new channel group". This starts as a copy of the default group.
  3. Click "Add new channel" and name it something like "AI assistants".
  4. Add a condition on Source with "matches regex" and paste your pattern.
  5. Click Reorder and drag the new channel above Referral. Save the group.

Order matters. GA4 puts each visit in the first channel whose rule it matches. If Referral sits above your AI channel, Referral wins and your AI row stays empty.

Custom channel groups apply to your reports retroactively, so you see past data straight away. A standard GA4 property can have 2 custom groups on top of the default one, with up to 50 channels each. Don't waste a slot on a test.

Step 2: pick a regex you can read

Google's help page gives an example pattern. Read it before you paste it. It starts with ^.*ai|, which is broad: depending on how the match is applied, it can catch sources that just end in or contain "ai" and have nothing to do with AI assistants.

We prefer a short, anchored list of exact hostnames. It's boring, and you can see what it does:

^(chatgpt\.com|chat\.openai\.com|perplexity\.ai|www\.perplexity\.ai|claude\.ai|gemini\.google\.com|copilot\.microsoft\.com|chat\.deepseek\.com|grok\.com|meta\.ai)$

Treat it as a starting point, not a standard. Before you save it, open an exploration, list Session source for the last 90 days, and check which hostnames actually show up for you. Add what you see, drop what you never get. Google's own note says to update the regex when the list of assistants changes.

Don't add google.com. AI Overview and AI Mode clicks share it with normal search, so you would just move your organic traffic into the AI row.

Step 3: know where the number lies

Here is the part most setup guides skip. An AI channel in GA4 only counts visits that arrive with a referrer or a tag that says where they came from. Everything else lands in Direct.

Tags can disappear overnight. ChatGPT has been adding utm_source=chatgpt.com to links. From around Oct 9, 2026, many links in its answers arrived without the tag and without a referrer, so those visits showed up as Direct. Profound, an AI search analytics company, reported that in its collected answers, the share with at least one tagged source link fell from about 98% on October 8 to 75% on October 9 and 66% by October 14.

On Oct 15, 2026, Search Engine Roundtable updated its story: the LinkedIn post it was based on now said it was a bug and that ChatGPT was tagging its links again. OpenAI itself hadn't commented in either article we read. If your ChatGPT row dropped that week while Direct rose, annotate it. That's a measurement change, not proof you lost visibility.

Some apps never pass a referrer. Ahrefs reports that some AI platforms strip referral data entirely, and that some track on the web but not in their desktop apps. Their advice: treat AI referral numbers as an undercount.

Most of the influence never clicks. Someone asks an assistant for a recommendation, reads your name, and types your URL later. That's a Direct visit, or a branded Google search. No regex will find it.

Step 4: fill the gaps

  • Ask people. Add "How did you hear about us?" to your signup, checkout or contact form, with options like ChatGPT, Perplexity, another AI assistant, and Google AI Overviews. Ahrefs recommends this too.
  • Check Search Console for Google's AI features. Google says clicks from AI Overviews and AI Mode are included in the Performance report under the "Web" search type. They aren't broken out separately there.
  • Watch Direct next to your AI row. If AI drops and Direct rises on the same pages, suspect tracking first.
  • Measure mentions, not just clicks. Traffic tells you who clicked. It doesn't tell you whether assistants mention you at all, or who they mention instead.

Where we fit

We built Answer Checkup because the click count was the only number most small sites had, and it misses most of the story.

Our free scan checks the step before any of this: whether AI crawlers can read your site at all. It fetches your pages and looks at robots.txt rules for AI crawlers, llms.txt, schema.org JSON-LD, your title and meta description, whether your main content is in the raw HTML, and your sitemap. If a search crawler is blocked, there's nothing for an assistant to cite, and nothing for GA4 to count.

Our free scan reads your site itself. It does not ask any AI engine. Our paid reports, coming soon, ask buyer-style questions through the OpenAI API with web search and the Perplexity API, and show your share of voice and the domains those answers cite. API answers are close to what people see in the consumer apps, but they are not the same thing, so we treat them as a sample, not a mirror.

None of this guarantees you'll be mentioned or recommended. It tells you where you stand.

FAQ

Does GA4 track ChatGPT traffic automatically?
Partly. The default AI Assistant channel catches visits GA4 can identify from its list of AI referrers. Visits with no referrer and no tag go to Direct.
Why is my AI traffic so low?
Often because it's undercounted. Some apps don't pass a referrer, and many people read an answer without clicking. It can also mean assistants rarely mention you.
How do I track AI Overview traffic in GA4?
You can't separate it in GA4. Google counts AI Overviews and AI Mode under Organic Search. Search Console includes them in the Web search type.
What does utm_source=chatgpt.com mean?
It's a tag on links clicked in ChatGPT that tells your analytics the visit came from ChatGPT.

Sources

All fetched Oct 15, 2026.

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Answer Checkup is not affiliated with OpenAI, Perplexity, Google or Microsoft.