Find your ChatGPT traffic in GA4

Tick the AI assistants you care about. You get a regex for GA4, the steps for an AI channel that sits above Referral, and a Looker Studio formula. It all runs in your browser; nothing gets sent anywhere.

A GA4 regex

For Session source, matches regex: an Exploration filter, a comparison in a report, or the channel below (where the dimension is called Source).

^(.*[.])?(chatgpt[.]com|chat[.]openai[.]com|perplexity[.]ai|gemini[.]google[.]com|claude[.]ai|copilot[.]microsoft[.]com|chat[.]deepseek[.]com|grok[.]com|chat[.]mistral[.]ai|meta[.]ai)$

B An AI assistants channel above Referral

In GA4, open Admin, then Data display, then Channel groups.
Click Create new channel group. It starts as a copy of the default group; give it a name.
Click Add new channel and call it AI assistants.
Add a condition: Source, matches regex, then paste the regex above. Save the channel.
Click Reorder and drag AI assistants above Referral. If the list has Google's own AI Assistant channel, put yours above that too. Apply, then save the group.
In Reports, open Traffic acquisition and switch the table's first column to your new group.

C Looker Studio formula

In your GA4 data source, add a calculated field, paste this in as its formula and use the field in place of the default channel group.

CASE
  WHEN REGEXP_MATCH(Session source, "^(.*[.])?(chatgpt[.]com|chat[.]openai[.]com|perplexity[.]ai|gemini[.]google[.]com|claude[.]ai|copilot[.]microsoft[.]com|chat[.]deepseek[.]com|grok[.]com|chat[.]mistral[.]ai|meta[.]ai)$") THEN "AI assistants"
  ELSE Session default channel group
END

Why AI visits hide in Referral and Direct

GA4 files a visit by where it came from. A click from a chat answer that brings its referrer along becomes chatgpt.com / referral and lands in Referral, next to every blog that ever linked you. Three more ways GA4 AI referral traffic goes missing:

No referrer at all. Apps, in-app browsers and copied links often arrive without one. GA4 calls that Direct, and no filter can pull it back out.
A UTM with no medium. ChatGPT adds utm_source=chatgpt.com to many links. Without a utm_medium next to it the medium is (not set), and the session can end up in Unassigned.
Google's own AI. Clicks from AI Overviews and AI Mode count as Organic Search; Google's channel definitions say so. There's no way to split them from regular Google clicks.

GA4's built-in AI Assistant channel

In 2026 Google added an AI Assistant channel to GA4's default channel group. Its definition names ChatGPT, Gemini, DeepSeek, Copilot and Grok as examples, leaves out AI Overviews and AI Mode, and doesn't publish the full list of assistants it recognises. Fine as a start. The catch is you can't read that list: if an assistant you care about still shows up under Referral, it isn't on it.

Your own channel fixes that. You pick the hostnames, you can read them, and it matches on the session source, so the UTM-tagged ChatGPT visits count too. Put it above Referral, and above Google's AI Assistant channel if your list has one, so each AI visit lands in one bucket, not two.

What to do with the number

Traffic is the end of the chain. Before anyone clicks, an answer has to name you or cite your page. The AI citation tracker records which pages the engines cite; the AI rank tracker records who gets named, and in what order. If your AI numbers sit near zero, first make sure AI crawlers get into your site at all.

Questions people ask

Doesn't GA4 sort out ChatGPT traffic on its own now?

Partly. In 2026 the default channel group got an AI Assistant channel for sources like ChatGPT, Gemini, DeepSeek, Copilot and Grok. Google doesn't publish the full list, and UTM-tagged visits can slip past it. A channel built on your own regex is a list you can read.

Why does chatgpt.com show up in Unassigned?

Because the link carried utm_source=chatgpt.com with no utm_medium. GA4 sets the medium to (not set), and when no channel rule fits a session it files it under Unassigned. A channel that matches on Source catches it anyway.

Can I see traffic from Google's AI Overviews?

Not in GA4. Google counts AI Overviews and AI Mode clicks as Organic Search, mixed in with ordinary Google clicks. What you can track is whether the overview names and cites you, and that's a job for a tracker.

Where else does the regex work?

Anywhere GA4 takes a regex on Session source: an Exploration filter, a comparison in a report, or a channel condition (there the dimension is just Source). The [.] in it means a literal dot, so there are no backslashes to escape.

Does this tool send or store anything?

No. It builds the text in your browser. No network request, nothing saved, no account.

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