# How to track ChatGPT, Gemini and Perplexity traffic in GA4 Canonical URL: https://www.martechdevs.com/blog/track-ai-traffic-ga4 By [Jafrin Akter Alo](https://www.martechdevs.com/authors/jafrin-akter-alo) Data Engineer and Co-founder, martechdevs Published: 2025-08-27 Last updated: 2026-10-12 GA4 has a default channel called AI Assistant for visits from chat tools such as ChatGPT, Gemini, DeepSeek, Copilot and Grok. Open Reports, Acquisition, Traffic acquisition and look for that row. To catch assistants GA4 files under Referral, add a custom channel group with a source regex. Clicks from Google's AI Overviews and AI Mode stay in Organic Search. GA4 picks a visit's channel from its source and medium. When the referrer is on Google's list of AI assistants, GA4 sets the medium to `ai-assistant` and the visit lands in the AI Assistant channel. A visit from an assistant off the list stays in Referral, and a visit with no referrer lands in Direct. So the AI Assistant row is a floor, and the number in the board deck needs two more signals next to it. At martechdevs, we add this as part of [GA4 and tracking implementations](https://www.martechdevs.com/analytics-tracking), next to the server-side tagging and conversion work. Everything below runs in your own GA4 property and CRM. ## Does GA4 track ChatGPT traffic? Yes. Google's channel definitions describe AI Assistant as the channel for visits from sources like ChatGPT, Gemini, DeepSeek, Copilot and Grok ([Google Analytics Help](https://support.google.com/analytics/answer/9756891)). A visit lands there when its medium is exactly `ai-assistant`, or when its referrer matches Google's list of AI assistants. In that case GA4 sets the medium to `ai-assistant` and the campaign to `(ai-assistant)`. Google doesn't publish the full list. It says the definitions may change as the market changes, and that it reviews requests to add sources at least once a year. Clicks from Google's own AI Overviews and AI Mode are left out and count as Organic Search. ## Where do you see AI traffic in GA4? 1. Open **Reports**, then **Acquisition**, then **Traffic acquisition**. The table groups sessions by channel. 2. Find the **AI Assistant** row. If it isn't there, no session matched in that date range. 3. Change the dimension to **Session source / medium** and search for `ai-assistant` to see which assistant sent each session. 4. Add your key events as columns, so signups or purchases from AI traffic sit next to the sessions. 5. Open **Engagement**, then **Landing page**, and filter on session source to see which pages AI tools send people to. Those landing pages are the ones AI answers cite. Check them first: is every fact current, does the page say what you sell, and is there a next step? ## How do you catch the AI tools GA4 doesn't classify? Add a custom channel group with an AI channel above Referral. Custom channel groups apply to past data in reports, so the history fills in as soon as you save. Google's own help page uses AI assistants as its example and names ChatGPT, Gemini, Microsoft Copilot, Claude and Perplexity ([Google Analytics Help](https://support.google.com/analytics/answer/13051316)). 1. In **Admin**, under **Data display**, open **Channel groups**. You need Editor access on the property. 2. Click **Create new channel group**. It starts as a copy of the default group. 3. Click **Add new channel**, name it AI assistants, and add a condition: **Source** matches regex, with the pattern below. 4. Click **Save channel**, then **Reorder**. Drag AI assistants above **Referral** and click **Apply**. 5. Save the group. In Traffic acquisition, switch the primary dimension to your new channel group. ```text .*(chatgpt|openai|perplexity|claude\.ai|gemini\.google|copilot|deepseek|grok|meta\.ai|mistral).* ``` Keep the pattern in a doc and update it when a new assistant starts sending traffic. A standard GA4 property allows two custom channel groups and GA4 360 allows five, with up to 50 channels in each. For a quick look without changing settings, build a Free-form exploration with Session source as the row and a filter on Session source matching the same pattern. ## What does GA4's AI Assistant channel miss? Most of the influence. Profound tracked brand site visits after AI mentions across more than 2 million conversations from January to June 2026. Visits ran 1.5 to 2.5 times the expected baseline over the next 7 days, over 97% of them carried no UTM, and in June 2026 about 2.5% of ChatGPT visits had a trackable AI referral parameter ([Profound, July 2026](https://tryprofound.com/blog/the-ai-mention-effect)). - **AI Overviews and AI Mode:** Google counts these clicks as Organic Search, and Search Console reports them inside Web performance ([Google Search Central](https://developers.google.com/search/docs/appearance/ai-features)). - **People who read the answer and come back later:** they search your name or type your URL, so the visit lands in Organic Search or Direct. - **Links copied out of the chat:** a pasted link arrives with no referrer and lands in Direct. ## How do you measure the AI traffic GA4 can't see? Use three signals together and report them side by side. 1. **The AI Assistant channel, or your custom AI channel,** for sessions and key events you can attribute directly. 2. **A "How did you hear about us?" field** on signup and demo forms, with ChatGPT, Perplexity, Gemini, Claude and Google's AI results as options. Store the answer as a property in HubSpot or Salesforce, so it travels with the deal. 3. **Pipeline by that property** in the CRM, so the board sees AI-influenced revenue next to AI-referred sessions. In Mixpanel or PostHog, the initial referring domain does the same job as GA4's source. Filter it with the same list of domains. ## Is AI traffic worth tracking? It is small, and it converts. BrightEdge data put ChatGPT at 95.1% of AI referral traffic to websites in August 2026, with Gemini at 2.4%, Perplexity at 1.1% and Claude at 0.8% ([The Next Web, September 2026](https://thenextweb.com/news/chatgpt-ai-referral-traffic-95-percent-brightedge)). - Ahrefs found AI search sent 0.5% of its visits but 12.1% of its signups, about 23 times the conversion rate of organic search. That's one site's data ([Ahrefs, June 2025](https://ahrefs.com/blog/ai-search-traffic-conversions-ahrefs/)). - Semrush reports the average AI search visitor is worth 4.4 times a traditional organic visitor on conversion rate. It's a vendor figure, and the raw rates weren't published ([Semrush, July 2025](https://www.semrush.com/blog/ai-search-seo-traffic-study/)). - HubSpot surveyed more than 3,000 CRM buyers and found 42% used AI search during evaluation, and those buyers were 36% more likely to purchase ([HubSpot, January 2026](https://www.hubspot.com/company-news/aeo-data-buyers-using-ai-search-more-likely-to-purchase)). If AI answers already send you signups, keep the pages they cite current. AI answers lag on renamed products and changed prices, and a stale page is what they quote. ## What does this look like for a 20-person SaaS? An example setup for a 20-person B2B SaaS on GA4 and HubSpot, in the order we would run it. The numbers will be yours. 1. **Day one:** check Traffic acquisition for the AI Assistant row and note the top five landing pages from it. 2. **Same day:** add the custom AI channel group above Referral and compare it with the default channel. The gap is AI traffic GA4 files as Referral. 3. **Week one:** add "How did you hear about us?" to the demo form, map it to a HubSpot contact property and copy it to the deal. 4. **Month one:** report sessions, signups and pipeline by AI source in one view, and review the pages AI tools cite. ## Checklist: AI traffic in GA4 and the CRM - [ ] AI Assistant row checked in Traffic acquisition - [ ] A custom channel group with an AI channel above Referral - [ ] The regex written down and reviewed every quarter - [ ] Key events shown next to AI sessions - [ ] Landing pages from AI traffic checked for current facts and a next step - [ ] "How did you hear about us?" with AI options on signup and demo forms - [ ] That answer stored on the CRM contact and the deal - [ ] AI-influenced pipeline reported next to AI sessions ### Want AI traffic measured end to end? At martechdevs, we set up GA4, the CRM fields and the reporting as one fixed-price project, usually live in weeks. Your team owns all of it after handover. ## Frequently asked questions ### Does GA4 have an AI channel? Yes. GA4's default channel group includes AI Assistant, for visits from chat tools such as ChatGPT, Gemini, DeepSeek, Copilot and Grok. Google maintains the list of assistants and doesn't publish it in full. ### Why does ChatGPT traffic show as Direct? Many AI-influenced visits arrive without a referrer: a copied link, or a later visit typed into the browser. Profound found over 97% of visits after an AI mention carried no UTM. A "How did you hear about us?" field catches what GA4 misses. ### Does Perplexity traffic count as AI Assistant in GA4? Google's channel page doesn't name Perplexity among its examples, so check your own property. If Perplexity sessions sit in Referral, a custom channel group with a source regex moves them into an AI channel. ### Are AI Overviews clicks counted as AI traffic? No. Google counts clicks from AI Overviews and AI Mode as Organic Search, and Search Console reports them inside Web performance. ### Does a custom channel group change historical data? It applies to past data in reports, so you see the history as soon as you save it. The default channel group stays as it is. ### How many custom channel groups can a GA4 property have? Two on a standard property and five on GA4 360, each with up to 50 channels. ## Sources 1. Google Analytics Help, [[GA4] Default channel group](https://support.google.com/analytics/answer/9756891), read 11 October 2026. 2. Google Analytics Help, [[GA4] Custom channel groups](https://support.google.com/analytics/answer/13051316), read 11 October 2026. 3. Profound, [The AI mention effect](https://tryprofound.com/blog/the-ai-mention-effect), 1 July 2026. 4. Google Search Central, [AI features and your website](https://developers.google.com/search/docs/appearance/ai-features), updated 10 December 2025. 5. The Next Web (BrightEdge data), [ChatGPT sends 95% of AI referral traffic](https://thenextweb.com/news/chatgpt-ai-referral-traffic-95-percent-brightedge), 24 September 2026. 6. Ahrefs, [AI search traffic conversions](https://ahrefs.com/blog/ai-search-traffic-conversions-ahrefs/), 16 June 2025. 7. Semrush, [AI search and SEO traffic study](https://www.semrush.com/blog/ai-search-seo-traffic-study/), 21 July 2025. 8. HubSpot, [AEO data: buyers using AI search are more likely to purchase](https://www.hubspot.com/company-news/aeo-data-buyers-using-ai-search-more-likely-to-purchase), January 2026, updated 15 September 2026.