How to Track AI Traffic in GA4 (ChatGPT, Perplexity)

AI assistants now send real visits: someone asks ChatGPT for a recommendation, clicks your link, and lands on your site. GA4 now files the assistants Google recognizes under its own AI Assistant channel, but Google keeps that list, and the visits it misses still land in Referral with dozens of other sources. Five minutes of setup puts every assistant on one line you control.

Quick answer

GA4’s default channel group now has an AI Assistant channel for the assistants Google recognizes. To cover the rest and decide the list yourself, filter or group sessions whose source matches a regex of AI assistant hosts: chatgpt.com, perplexity.ai, gemini.google.com, copilot.microsoft.com, claude.ai and the rest. Use it in an exploration for a quick answer, or in a custom channel group so every report shows one AI assistants channel. Clicks from Google AI Overviews and AI Mode are the exception: they arrive as google / organic and cannot be separated in GA4.

This guide covers what GA4’s own channel catches, the regex, both ways to use it, and the caveats that explain why the number is a floor rather than a total.

What GA4 now does on its own

In 2026 Google added an AI Assistant channel to GA4’s default channel group. When a session’s referrer matches Google’s list of AI assistants, GA4 sets the medium to ai-assistant and the campaign to (ai-assistant), and the session lands in that channel with no setup at all. Look for the AI Assistant row in your Traffic acquisition report.

Two limits make it a starting point rather than the whole answer. Google’s documentation gives ChatGPT, Gemini, DeepSeek, Copilot and Grok as examples but does not publish the full list, so you cannot see which assistants count or add the ones it misses. And by design it excludes Google’s own AI Overviews and AI Mode. The regex below fixes the first limit; nothing in GA4 fixes the second.

The regex for AI assistant traffic

This is the pattern Rank Prompt itself uses to recognize AI referrals in the GA4 data it reads. It matches 22 AI assistants by their hosts, as whole domain labels, so chat.openai.com counts as ChatGPT while a lookalike domain does not:

.*(^|\.)(chatgpt|openai|gemini\.google|bard\.google|aistudio\.google|notebooklm|copilot\.microsoft|copilot|perplexity|claude|anthropic|poe\.com|grok|x\.ai|you\.com|pi\.ai|inflection\.ai|character\.ai|lechat|mistral|huggingface|huggingchat|phind|komo\.ai|andisearch|search\.brave|arc\.net|meta\.ai|cohere|deepseek)(\.|$).*

It covers ChatGPT, Gemini, NotebookLM, Copilot, Perplexity, Claude, Poe, Grok, You.com, Pi, Character.ai, Le Chat, Mistral, HuggingChat, Phind, Komo, Andi, Brave Leo, Arc Browser, Meta AI, Cohere and DeepSeek. The leading and trailing .* let it work whether a GA4 field matches the whole value or part of it.

Option 1: an exploration, for a quick answer

Use this when you want to know, today, how many sessions AI assistants sent and where they landed:

1. In GA4, open Explore and start a Blank exploration.
2. Add the dimensions Session source / medium and Landing page + query string.
3. Add the metrics Sessions, Engaged sessions and Key events.
4. Drag the dimensions into rows and the metrics into values.
5. Add a filter on Session source, choose matches regex, and paste the pattern above.

You now have every AI-referred session, the assistant that sent it, and the page it landed on. The landing pages are the useful part: they are the pages AI answers are sending people to, and usually the ones worth improving first.

Option 2: a custom channel group, for every report

An exploration answers one question. A channel group changes how GA4 sorts traffic everywhere, so AI assistants show up next to Organic Search and Paid Search in your standard reports.

1. Go to Admin, then Data display, then Channel groups.
2. Choose Create new channel group. GA4 starts from a copy of the default channels, AI Assistant included, so you do not lose any.
3. Add a new channel named AI assistants, with the condition Source matches regex, and paste the pattern.
4. Save, then reorder the channels so AI assistants sits above both AI Assistant and Referral. GA4 assigns each session to the first channel whose rule matches, so if either comes first, your AI visits end up split across channels.
5. In your reports, switch the primary dimension to your new channel group.

Custom channel groups apply to historical data as well, so the new channel fills in your past months straight away.

Why AI Overviews and AI Mode clicks show as google / organic

This is the question behind most confused AI traffic reports. When someone clicks a link inside Google AI Overviews or AI Mode, the visit comes from google.com, exactly like a click on a regular result. GA4 files it as google / organic, its AI Assistant channel leaves Google’s AI features out by design, and nothing in the session tells you it started in an AI answer.

Search Console only helps in part. The generative AI performance report Google added in June 2026 shows impressions for AI Overviews and AI Mode, but no clicks, CTR or position, and the clicks themselves stay inside the Web search totals.

That means your GA4 AI assistants channel shows ChatGPT, Perplexity, Claude and the others, but not Google’s own AI features. To know whether Google AI Mode (AI Overviews) names your brand, you have to look at the answers themselves: run the same prompts on a schedule and record who gets named and cited.

Why the number is a floor

Even with the regex in place, some AI-driven visits never show up as AI:

• Apps without referrers. Visits from some mobile and desktop assistant apps arrive with no referrer and land in Direct.
• Copied links. A user who copies a URL from an answer into a new tab arrives as Direct too.
• Links that carry their own tags. ChatGPT adds utm_source=chatgpt.com to many outbound links, which helps: GA4 then reports the source even when the referrer is missing.

So treat the AI assistants channel as the part you can prove, and watch its trend rather than its absolute size. A growing line, landing on the pages you optimized, is the signal that matters.

Connecting AI traffic to AI visibility

GA4 tells you what AI assistants sent you. It cannot tell you what they said about you when they did not send anyone. The two numbers belong side by side: visibility is how often assistants name and cite you, traffic is how often that turns into a visit.

Rank Prompt’s analytics connects to GA4 with read-only access and separates sessions from the same 22 AI assistants automatically, shows the landing pages they send people to, and puts sessions, users and page views next to your AI visibility score for the same dates. It also reads Search Console, so the queries Google already shows you for sit in the same place as the prompts AI answers. The GA4 setup guide walks through the connection, and it works on every plan, free included.