The short answer
Open Reports → Acquisition → Traffic acquisition and look for the AI Assistant channel, or set the primary dimension to Session source and look for chatgpt.com. That shows ChatGPT visits that arrived with a referrer or a utm_source=chatgpt.com tag. It doesn't show ChatGPT visits that arrived with neither, which GA4 counts as Direct, and it can never show ChatGPT reading your pages, because that happens without JavaScript.
Where ChatGPT visits appear in GA4
GA4 sorts every session into a channel using its default channel group. According to Google's channel definitions, AI Assistant is "the channel by which users arrive at your site from sources like ChatGPT, Gemini, Deepseek, Copilot, or Grok", and GA4 sets the medium to ai-assistant when the referrer matches its list of assistants. It excludes Google's AI Overviews and AI Mode, which arrive as Google search.
A ChatGPT visit can reach GA4 in three ways:
| How the visit arrives | What GA4 shows |
|---|---|
With chatgpt.com as the referrer | AI Assistant channel, source chatgpt.com |
With utm_source=chatgpt.com but no referrer | Source chatgpt.com; the channel depends on the medium, if any |
| With neither | Direct, source (direct) |
To see them all in one place, use an exploration: dimensions Session source / medium and Landing page, filtered to sources containing chatgpt. Add Session default channel group to see which ones GA4 placed in AI Assistant.
Why so much of it lands in Direct
Two things remove the evidence that a visit came from ChatGPT.
No referrer. When a link opens from a mobile app, or in a new tab with the browser's noreferrer setting, the browser sends no referrer at all. GA4 then relies entirely on the campaign tag.
No tag. ChatGPT has added utm_source=chatgpt.com to many of the links it cites. Since GPT-6 began rolling out on 7 October 2026, that tag has been missing from many links in answer text. Search Engine Journal reported on 15 October that ChatGPT-attributed sessions fell sharply from 9 October across several datasets, and that an Adobe product director saw Direct visits rise on the same pages that lost ChatGPT visits. OpenAI hadn't explained the change publicly when we wrote this; we cover what's known in why ChatGPT referral traffic dropped.
With no referrer and no tag, a visit from ChatGPT is indistinguishable from someone typing your address, and GA4 files it under Direct.
What GA4 can't see at all
Before a person clicks anything, ChatGPT has usually already read your page. When someone asks ChatGPT a question that needs the web, OpenAI fetches pages with the ChatGPT-User agent, and its search index is built by OAI-SearchBot (OpenAI's crawler documentation). Neither runs JavaScript, so the Google tag never loads and GA4 never records them.
That means GA4 can't tell you which pages ChatGPT reads, how often, or whether it got an error when it tried. Those requests reach only your server, CDN or hosting platform.
How to measure what GA4 misses
- Annotate 7 to 9 October 2026 in your reports, so a fall in ChatGPT sessions isn't read as a fall in interest.
- Watch Direct on the pages ChatGPT used to send. If Direct rose on your top ChatGPT landing pages when ChatGPT fell, that is probably the same visitors without a label.
- Read your server's view. Count requests from
ChatGPT-UserandOAI-SearchBot, and check each one's address against OpenAI's published IP lists, because anyone can copy a user agent. Our guide to tracking AI crawlers shows how.
LogZuno does the third step for you: AI visibility reads your server or CDN traffic, verifies each AI fetch against its operator's list, and marks a Direct visit as Likely ChatGPT when it lands on a page shortly after a verified ChatGPT fetch of that page, in a window measured from your own tagged visits. Proven and likely visits are kept apart, so you always know which is which.