The short answer
GA4 now has a native AI Assistant channel, but it misses some AI traffic: some platforms aren't recognized, some visits lose their referrer, and Google's own AI features count as organic search. Build a custom channel group that matches AI sources by domain, and read Search Console separately for AI Overviews and AI Mode.
Key takeaways
- The native GA4 AI Assistant channel is insufficient because it misses non-recognized platforms and drops referrer data.
- Google AI Overview traffic is aggregated under standard organic search and requires manual analysis in Search Console.
- To get defensible data, build a custom GA4 channel group using regex to match source domains and add self-reported attribution to forms.
"How much traffic do we get from AI?" sounds like a two-minute question. In practice, AI visits are scattered across Referral, Direct, Unassigned, and Organic Search.
The good news: you can get a defensible number in an afternoon. Here's how.
What does GA4's AI Assistant channel count?
In May 2026, Google added an AI Assistant channel to GA4's default channel group. When GA4 recognizes a referrer as an AI assistant, it tags the session with the medium ai-assistant.1
That's real progress. But Search Engine Journal's analysis found the list of recognized platforms changed within weeks of launch, and that Perplexity wasn't on it.1 Treat the native channel as a starting point, then check what it leaves out.
Why does it undercount?
AI visits hide in four places.
| Where it lands | Why | What you can do |
|---|---|---|
| Referral | The platform isn't on GA4's recognized list, or the visit predates the channel in your property | Match the source domain in a custom channel group |
| Unassigned | Some in-app browsers keep the source but drop the medium | Match on source alone, ignoring medium |
| Direct | Mobile apps and copied links often send no referrer at all | Can't be fixed in GA4; ask "how did you hear about us?" on forms |
| Organic Search | Visits from Google AI Overviews and AI Mode count as Google organic | Read Search Console instead (see below) |
What about Google AI Overviews and AI Mode?
Google includes traffic from its AI features in the Search Console Performance report, under the Web search type.2 It isn't broken out separately, so you can't isolate it as its own line.
What you can do is watch the pattern. Rising impressions with falling clicks on informational queries is a common sign that an AI Overview is answering the question on the results page.
Traffic is the smallest part of AI's effect. A buyer can read ChatGPT's shortlist, never click, and type your URL a week later. That visit shows up as Direct. Pair traffic data with a self-reported attribution field and with regular checks of what AI engines actually say about you.
How do you set it up?
Check the native channel.
In GA4, open Reports > Acquisition > Traffic acquisition and look for the AI Assistant channel.
Create a custom channel group.
In Admin > Data display > Channel groups, create a new group and add a channel called AI.
Match on source, not medium.
Use a "Source matches regex" condition with the AI domains you care about. A starting pattern:
(^|\.)(chatgpt\.com|openai\.com|perplexity\.ai|claude\.ai|gemini\.google\.com|copilot\.microsoft\.com|deepseek\.com|grok\.com)$
Put the AI channel above Referral and Organic.
Channel order decides which rule claims a session first. SEJ notes that custom channel groups apply to historical data too, so you can see trends from before the native channel existed.1
Add one form field.
"How did you first hear about us?" with an AI assistant option catches the Direct traffic GA4 never will.
Review the regex every quarter. New AI products launch and domains change, and SEJ recommends the same cadence.1
You won't get a perfect number. You will get one you can explain, trend, and defend in the board meeting.
Read next: What is share of answer, and how do you measure it?
The bottom line
You won't get a perfect number. You will get one you can explain, trend, and defend in the board meeting.
Sources
- Search Engine Journal, GA4's AI Assistant Channel Undercounts Your AI Traffic: How To Build One That Doesn't, Itamar Blauer, July 15, 2026. searchenginejournal.com/ga4s-ai-assistant-channel-undercounts-your-ai-traffic-how-to-build-one-that-doesnt/580133
- Google Search Central, AI features and your website, last updated December 10, 2025. developers.google.com/search/docs/appearance/ai-features
About the author
Aimee van der Haar
Aimee founded Bearly Creative to give great startups and tech companies the marketing they deserve. She works across strategy, design, content, and AI search, and she still does the work herself.
