utm_source=chatgpt.com is a tag ChatGPT adds to the links it shows, so your analytics can tell that a visitor came from a ChatGPT answer. OpenAI's own help page said so: "ChatGPT automatically includes the UTM parameter utm_source=chatgpt.com in referral URLs" (OpenAI Help Center, Publishers and Developers FAQ, copy of 4 Oct 2026, checked 14 Oct 2026). In Google Analytics 4 (GA4), these visits now land in a default channel called AI Assistant. To see Perplexity, Gemini, Copilot and Claude visits together, add a custom channel group with one rule, shown below.
Traffic is only half of the picture. An AI answer can name your brand and send no click at all. This guide covers both: how to count the visits, and how to measure the answers that never become visits.
What is utm_source=chatgpt.com?
It is a UTM parameter, a label added to the end of a link that analytics tools read to name the source of a visit. Google defines utm_source as the "Referrer, for example: google, newsletter4, billboard" (Google Analytics Help, URL builders, checked 14 Oct 2026). Here the referrer is chatgpt.com.
So a link to your page from a ChatGPT answer can arrive as yoursite.com/page?utm_source=chatgpt.com. Nothing is wrong with your site. The tag only labels the visit, and it does not change the page.
OpenAI's FAQ also said that publishers who allow OAI-SearchBot, its search crawler, can track this referral traffic in tools such as Google Analytics (same source). If your robots.txt blocks that crawler, start with our guide to AI crawlers and robots.txt.
Where do ChatGPT visits show up in GA4?
They show up in the AI Assistant channel of the default channel group. Google added it on 13 May 2026: "Google Analytics now provides a dedicated way to measure and analyze traffic originating from popular AI assistants" (Google Analytics Help, What's new, checked 14 Oct 2026).
Google's help page describes the channel as visits "from sources like ChatGPT, Gemini, Deepseek, Copilot, or Grok", and says "It excludes Google's AI Overviews and AI Mode" (Google Analytics Help, Default channel group, checked 14 Oct 2026). When the referrer matches a recognised AI assistant, GA4 sets the medium to ai-assistant and the campaign to (ai-assistant) (same source). Google gives examples, not a full list of the assistants it recognises.
Depra AI watches its own site this way. The AI Assistant channel appears in Depra AI's own GA4 property without any setup.
- Step 1: Open Reports, then Acquisition, then Traffic acquisition.
- Step 2: Keep the primary dimension on Session default channel group and find the AI Assistant row.
- Step 3: Change the dimension to Session source to split the row by chatgpt.com, gemini.google.com and the rest.
- Step 4: Add Landing page as a secondary dimension to see which of your pages the assistants link to.
How do I build a custom channel group for AI referrers?
Create a custom channel group with one channel whose source matches a regular expression (regex, a text pattern) of AI domains. Google's help page has its own "Example: AI assistants" pattern, and says "Custom channel groups can be applied to your reports retroactively" (Google Analytics Help, Custom channel groups, checked 14 Oct 2026). A standard property can have 2 custom groups (same source).
A custom group helps when you want one fixed list you control, and when you want to report each assistant by name.
- Step 1: In GA4, open Admin, then Channel groups under Data display. Copy the default channel group so every other channel stays the same.
- Step 2: Add a channel named AI referrals. Set the condition to Source, matches regex, and paste the pattern below.
- Step 3: Move AI referrals above Referral and Organic Search. GA4 puts a visit in the first channel it matches, so order matters.
- Step 4: Save, then pick the new group in the Traffic acquisition report.
chatgpt\.com|chat\.openai\.com|perplexity\.ai|gemini\.google\.com|copilot\.microsoft\.com|claude\.ai (a source regex for ChatGPT, Perplexity, Gemini, Copilot and Claude. Add a domain when another assistant starts sending visits.)
What does Search Console show?
Search Console shows clicks from Google's own AI features, not from ChatGPT or Perplexity. Google says sites that appear in AI Overviews and AI Mode are "reported on in the Performance report, within the "Web" search type" (Google Search Central, AI features and your website, checked 14 Oct 2026).
Google says these clicks are "included in the overall search traffic" (same source), so they are counted with your normal Google search clicks. GA4 keeps them out of its AI Assistant channel too.
So the full set of tools is GA4 for ChatGPT, Gemini, Perplexity, Copilot and Claude, and Search Console for Google search, AI Overviews and AI Mode together.
Why do the numbers look smaller than expected?
Some visits from AI answers lose their label on the way. Count what GA4 shows as a floor, not a total.
- Copied links: a person who copies a brand name or link from an answer and opens it later arrives as Direct or Organic Search.
- Apps: a click opened from an app can reach your site without a referrer. Without a referrer or a tag, it cannot match a channel rule.
- Missing medium: Google warns that "Missing UTM parameters will result in (not set) values being present in reporting" (URL builders, checked 14 Oct 2026). Check the Unassigned row as well.
- Unknown assistants: an assistant that is not on your regex, or on Google's list, stays in Referral.
What do AI traffic numbers miss?
They miss every answer that names your brand without a click. A shopper asks ChatGPT for the best sunscreen in India, reads three brand names, and later searches for one of them on Amazon.in or Google. GA4 records none of that as AI traffic. It also records nothing when the answer names your competitor and not you.
To see that part you need to measure the answers themselves: ask the questions your buyers ask, store each answer, and count how often your brand is named. That is AI visibility, the share of AI answers to your buyers' questions that name your brand.
Depra AI does that. AI visibility tracking asks your buying questions on ChatGPT, Gemini, Google AI Overviews and Perplexity from inside India or another market, stores every full answer, and shows how often each engine names you and your competitors. ChatGPT, Gemini and Google AI Overviews are checked daily on every plan. Perplexity is checked weekly on Starter, Growth and Scale, and daily on Enterprise.
Depra AI does not measure AI referral traffic or sales. Keep GA4 for visits and use Depra AI for the answers. The two together show whether more mentions lead to more visits.
| Question | GA4 | Search Console | Depra AI |
|---|---|---|---|
| Visits from ChatGPT, Gemini, Perplexity, Copilot | Yes | No | No |
| Clicks from AI Overviews and AI Mode | Not in AI Assistant | Yes, inside Web search | No |
| Answers that name you without a click | No | No | Yes |
| Answers that name a competitor and not you | No | No | Yes |
| Websites the answers cite | No | No | Yes |
What should I do with AI traffic data?
Use it to find the pages AI answers already link to, then make those pages better. The Landing page dimension in GA4 lists them.
- Check the page answers the question: put the direct answer in the first lines, with prices, sizes and facts written out.
- Keep crawlers in: confirm robots.txt lets OAI-SearchBot and the other AI crawlers read those pages.
- Compare with mentions: if visits are flat but ChatGPT visibility is rising, buyers may be reaching you by searching your name instead.