How to Track AI Traffic in GA4
Visits from ChatGPT and Perplexity are hiding inside your Referral and Direct numbers. A five-minute GA4 setup turns them into their own channel.
What you’ll learn
- Which referrer domains AI assistants send
- How to create an AI Assistants channel group in GA4
- Why part of AI traffic always shows up as Direct
- How to see AI bots that read your site without clicking
When someone clicks a source link inside an AI answer, the visit usually arrives with the assistant’s domain as the referrer. GA4 files these under Referral by default, mixed with every other website that links to you. Separating them takes one channel group.
Referrer domains to match
| Assistant | Referrer |
|---|---|
| ChatGPT | chatgpt.com, chat.openai.com |
| Perplexity | perplexity.ai |
| Gemini | gemini.google.com |
| Copilot | copilot.microsoft.com |
| Claude | claude.ai |
| DeepSeek | chat.deepseek.com |
| Grok | grok.com |
ChatGPT also adds utm_source=chatgpt.com to many outbound links, so those visits are tagged even when the referrer is lost.
The regex
(chatgpt\.com|chat\.openai\.com|perplexity\.ai|gemini\.google\.com|copilot\.microsoft\.com|claude\.ai|chat\.deepseek\.com|grok\.com)The AI Referral Traffic Tracker builds the current full version, with 15 assistants, for GA4, Looker Studio and Plausible.
Set up the channel in GA4
- Go to Admin → Data display → Channel groups.
- Copy the Default channel group. The default can’t be edited.
- Click Add new channel, name it AI Assistants.
- Condition: Source · matches regex · paste the regex.
- Drag the new channel above Referral. GA4 assigns a session to the first matching channel, so below Referral it never matches.
- Save, then pick the new group in Reports → Acquisition → Traffic acquisition.
Channel groups apply to past data too, so you see the history right away.
Why the numbers are too low
Treat the AI channel as a floor, not the full picture:
- Mobile apps often strip the referrer. Clicks from the ChatGPT or Perplexity apps can land as Direct.
- People copy links. A URL pasted into the address bar has no referrer.
- Many answers are never clicked. Your brand can be named and recommended without a visit.
A rising Direct share on pages that get cited is often hidden AI traffic.
Measure the bots, too
Referral data shows people. To see the AI crawlers that read your pages before they get cited, look at your server logs. The AI Bot Log Analyzer shows which AI bots crawl which pages, what errors they hit, and which “AI bots” are fake.