---
title: "How to track ChatGPT traffic in GA4 (AI referrals)"
description: "GA4 has an AI Assistant channel since May 2026, but ChatGPT often sends no referrer. Use utm_source=chatgpt.com and a custom channel group regex to count it all."
url: https://katman.pro/track-chatgpt-traffic-ga4
lang: en
updated: 2026-10-20
---

Guide Updated 20 Oct 2026

# How do I track traffic from ChatGPT in Google Analytics 4?

> Open Traffic acquisition in GA4 and look for the AI Assistant channel, which Google added on 13 May 2026. Then add a custom channel group that matches chatgpt.com and other assistants by source, not only by referrer, because many ChatGPT visits arrive with utm_source=chatgpt.com and no referrer at all: 79% did on our sample site. Put the new channel above Referral, compare landing pages and key events, and you’ll see AI visitors that would otherwise hide in Direct or Unassigned.

## Why ChatGPT visits hide in your reports

GA4 decides where a visit came from by two things: the UTM tags in the landing URL and the referrer the browser sends. ChatGPT traffic often has only the first. On our sample site, 79% of ChatGPT visitors arrived with `utm_source=chatgpt.com` in the link and no referrer at all (own measurement, 21 to 27 September 2026; see [the case study](https://katman.pro/case-studies/sample-site-first-7-days)). Visits from the apps, copied links and some browsers lose the referrer; visits without the tag either then look like Direct traffic.

We looked for an OpenAI page describing the tag on 15 October 2026 and couldn’t find a current one, so treat it as observed behavior, not a promise. The rule we use everywhere is simple: **a visit is ChatGPT if the referrer is chatgpt.com or the link carries utm\_source=chatgpt.com.**

## Step 1: check the built-in AI Assistant channel

GA4 added an “AI Assistant” channel to the Default Channel Group on 13 May 2026 ([GA4 What’s new](https://support.google.com/analytics/answer/9164320), read 15 Oct 2026). Google describes it as visits “from sources like ChatGPT, Gemini, Deepseek, Copilot, or Grok”, assigned when the medium is `ai-assistant` or the referrer matches its list of assistants, and it excludes AI Overviews and AI Mode ([GA4 default channel group](https://support.google.com/analytics/answer/9756891), read 15 Oct 2026). Google doesn’t publish the list on that page.

1.  Go to Reports, Acquisition, Traffic acquisition.
2.  Set the table to “Session default channel group” and look for AI Assistant.
3.  Switch the dimension to “Session source / medium” and search for `chatgpt`.

If you see `chatgpt.com` rows outside AI Assistant (in Unassigned, Referral or elsewhere), the built-in channel isn’t catching them, and Step 2 fixes that for your reports.

## Step 2: add a custom channel group by source

Google’s own steps ([GA4 custom channel groups](https://support.google.com/analytics/answer/13051316), read 15 Oct 2026):

1.  Admin, Data display, Channel groups (Editor access needed). Create a new channel group.
2.  Add a channel named “AI assistants” with the condition **Source matches regex** and the pattern below.
3.  Save, then reorder so “AI assistants” sits above Referral, as Google advises. Traffic goes to the first channel it matches.
4.  Pick the new group as the primary dimension in Traffic acquisition.

Google says custom channel groups apply to your reports retroactively, so you see past ChatGPT traffic too. Standard properties can have 2 custom groups.

### Example: the regex

Google’s help page offers a broad pattern built from pieces like `.*gpt.*` and `.*gemini.*`, which can catch any source that merely contains those letters. This one names hosts exactly and works whether GA4 matches the whole value or part of it:

```text
^(.*\.)?(chatgpt\.com|openai\.com|perplexity\.ai|claude\.ai|gemini\.google\.com|copilot\.microsoft\.com|copilot\.com|chat\.deepseek\.com|grok\.com)$
```

| Source value | Matches? |
| --- | --- |
| `chatgpt.com` (referrer or utm\_source) | Yes |
| `www.perplexity.ai` | Yes |
| `gemini.google.com` | Yes |
| `google` (organic, AI Overviews, AI Mode) | No, on purpose |
| `mail.google.com` | No |

Add a host when you see a new assistant in your source list. If you tag your own links in AI tools, use `utm_medium=ai-assistant` and Google’s channel picks them up too.

## Step 3: read the numbers that matter

-   **Landing pages:** add “Landing page” as a secondary dimension. On our sample site, 59% of ChatGPT visitors landed on two pages written for a customer’s situation (own measurement, first week).
-   **Key events:** compare sign-ups or purchases per session for AI assistants with other channels. Small numbers swing a lot; read weeks, not days.
-   **Direct:** if Direct grows when AI assistants grow, some untagged AI traffic is probably in there. You can’t recover it in GA4.

## What GA4 can’t see

-   **Bots.** GPTBot, OAI-SearchBot and ChatGPT-User don’t run your analytics script. Count them in server or CDN logs.
-   **Mentions without a click.** For that, see [how to track brand mentions in AI answers](https://katman.pro/track-brand-mentions-in-ai-answers) and [how to check if ChatGPT recommends you](https://katman.pro/check-if-chatgpt-recommends-your-site).
-   **Google’s AI features.** They count as Google organic. Search Console’s Generative AI performance report covers them.

## What Katman does here

[Katman](https://katman.pro/mcp) is an MCP server that runs inside your AI coding tool. `katman_generate` returns an analytics snippet that applies the ChatGPT rule above and a human filter, plus a server-side bot counter for Cloudflare Workers, Next.js, Express, Astro or SvelteKit, so crawler visits are counted where analytics can’t see them. Your coding tool adds them; Katman doesn’t touch your GA4 property. Katman Pro is $99 a month for up to 3 sites, with fix prompts and page briefs uncapped. Or have us do it: [Growth](https://katman.pro/done-for-you) writes 30 pages a month for you. More on [the measure step of the method](https://katman.pro/method).

Written by the Katman team, Rnify Limited. Google Analytics Help pages checked 15 October 2026; sample-site figures from the site’s own analytics, human sessions only (528 of 1,546), 21 to 27 September 2026, one sample site, our own product.

## Who this is not for

-   Sites on another analytics tool: the rule (chatgpt.com referrer or utm\_source=chatgpt.com) is the same, the menus aren’t.
-   Anyone who wants to know how often ChatGPT mentions them without a click: analytics only sees visits.
-   Ad campaigns on ChatGPT: those have their own conversion tracking in OpenAI’s Ads Manager.

## Frequently asked questions

### Does GA4 track ChatGPT traffic automatically?

Partly. Since 13 May 2026 the default channel group has an AI Assistant channel, set by the medium ai-assistant or by a referrer on Google’s list of assistants. Visits without a referrer can still land elsewhere, so check by source too.

### Why does ChatGPT traffic show up as Direct?

Because the visit arrives without a referrer, from an app, a copied link or a browser that strips it. When the link carries utm\_source=chatgpt.com, GA4 still records the source; without the tag, nothing tells GA4 it came from ChatGPT.

### What is utm\_source=chatgpt.com?

A tag on links that ChatGPT shows, which identifies the visit as coming from ChatGPT even with no referrer. 79% of our sample site’s ChatGPT visitors had only this tag (own measurement, 21 to 27 September 2026).

### Can I see past ChatGPT traffic with a new channel group?

Yes. Google says custom channel groups apply to your reports retroactively.

### Does GA4 count visits from AI Overviews or AI Mode?

Not in the AI Assistant channel: Google says it excludes AI Overviews and AI Mode. Those visits count as Google organic search; Search Console’s Generative AI performance report covers them.

### Can GA4 show how often ChatGPT crawls my site?

No. Crawlers don’t run your analytics script. Count GPTBot, OAI-SearchBot and ChatGPT-User in your server or CDN logs instead.

## Related pages

-   [**Our sample site’s first 7 days: 333 visitors from ChatGPT** A new consumer AI app got 333 ChatGPT visitors in week one; by day 26 ChatGPT brought 44% of sign-ups and 46% of subscription revenue. Updated 17 Oct.](https://katman.pro/case-studies/sample-site-first-7-days)
-   [**How do I track whether ChatGPT and other assistants mention my brand?** Three ways to track AI brand mentions: a fixed question set by hand, an API panel run, or a hosted tracker. What each sees, what it costs and how to log results.](https://katman.pro/track-brand-mentions-in-ai-answers)
-   [**How do I check whether ChatGPT, Claude and Perplexity recommend my site?** Ask 12 unbranded questions and 2 “What is \[brand\]?” ones logged out, then log who is named, recommended and cited. Why one answer misleads, and the API option.](https://katman.pro/check-if-chatgpt-recommends-your-site)
-   [**Does ChatGPT use Bing’s index?** ChatGPT search runs its own crawler, OAI-SearchBot, and sometimes uses partner search providers; Copilot runs on Bing. What that means and how to get into Bing.](https://katman.pro/does-chatgpt-use-bing)
-   [**The Katman method: research, plan, build, verify** Four steps, three gates and 15 prompts with acceptance criteria that make a site readable, quotable and recommendable by ChatGPT, Claude, Gemini and Perplexity.](https://katman.pro/method)
-   [**Katman MCP** Katman MCP runs in Cursor, Claude Code and VS Code: it scans your code, audits your live site like AI crawlers do and checks every fix. Katman Pro from $99/month.](https://katman.pro/mcp)

Updated 20 October 2026 · Katman