How to track AI agent traffic in Google Analytics 4

To see AI traffic in GA4 you combine three things: the native AI Assistant channel, a custom channel group for what it leaves out, and UTMs on the links your brand controls. None of the three solves it alone, and the sum of the three still leaves part of the traffic invisible. This article shows what to do and where the limit is.

It is worth starting with what changed. Since May 13, 2026, GA4 has a default channel called AI Assistant, with broad availability across properties from June. When the referrer matches a recognized assistant, Analytics records the medium as ai-assistant and the campaign as (ai-assistant), with no configuration on your part.

What GA4's native AI traffic channel covers today

This is where the check we did on August 29, 2026, straight from the official documentation, is worth it, because this information has changed since the announcement.

The current definition of the default channel group describes AI Assistant as the channel for users arriving from sources such as ChatGPT, Gemini, Deepseek, Copilot or Grok. The May announcement mentioned ChatGPT, Gemini and Claude. The published list has changed since then, which is the best argument for you to check the page before reporting any number: it evolves without notice.

Two important exclusions are in the documentation itself:

Google's AI Overviews and AI Mode are left out. They are classified as Organic Search, by official definition. If you expected to see Google's AI in this channel, it is not there.

Perplexity does not appear in the definition. Traffic coming from it keeps falling into Referral.

Why the native channel is not enough

Besides the incomplete list, there is a detail that gets in the way of historical reading: the channel applies going forward. Sessions before May remain classified as Referral or Direct, so the historical series of your AI traffic does not rebuild itself.

This is where the custom channel group comes in, which has an advantage the native one does not: Google's documentation confirms that custom channel groups can be applied to reports retroactively. You recover the history and cover the platforms that were left out.

How to set up the custom group

The path is Admin, under Data display, and then Channel groups. You need editor access or higher.

1. Create a new group, which starts as a copy of the default group.
2. Add a channel and give it a clear name, such as "AI Assistants".
3. Set the condition to "matches regex" and list the domains you want to capture.
4. Save the channel and then save the group.

Google's own help center has a regex example for AI assistants, covering ChatGPT, Gemini, Copilot, Claude and Perplexity. It is worth using it as a starting point and adjusting it to the domains that appear in your Referral report, because the list of assistants changes.

Two practical limits: a standard property allows only two custom groups, and the channel definition is not case-sensitive.

Resource · In PortuguesePrompt Guide for Marketing and Sales70 prompts with questions about marketing, sales and behavior to ask your data.Download the guide

The priority order trap

This is the part most people get wrong, and it silently brings down the whole configuration.

GA4 classifies each session in the first channel whose definition matches, following the order in which the channels are in the group. If your AI assistants channel sits below Referral, Referral will capture the sessions first, and the new channel appears empty. You conclude that you have no AI traffic, when in fact you have a badly positioned rule.

The guidance is in the documentation: reorder the list so that the AI assistants channel appears above Referral. If needed, it can also sit above Organic Search.

After reordering, check in Acquisition, in the traffic acquisition report, using your custom group as the primary dimension.

UTMs on the links you control

Not all AI traffic depends on a referrer. When you publish a link yourself, whether in a resource that will be cited or in a campaign, tag it with UTMs.

It is the only layer of tracking that does not depend on what the AI platform decides to send in the header. A session with UTMs is attributed by the parameters you defined, and not by the channel rule.

If your operation's UTM standard is not yet settled, it is worth first reading the guide on naming mistakes that break the report, because a channel rule built on inconsistent parameters returns a wrong number that looks right.

The honest limit: part of this remains invisible

This is where most tutorials stop telling the story. Three gaps remain after everything is configured.

A session with no referrer falls into Direct. Assistants that open the link in an in-app browser, or that run in the app, often do not send the header. No channel rule reaches that.

An answer with no click generates no session. If the AI answers the question using your content and the person does not click, there is no event to measure. The influence happens and GA4 does not see it.

Google's AI is in another channel. AI Overviews and AI Mode count as Organic Search, so part of your exposure to AI will never show up in the AI Assistant channel.

The practical conclusion is that every AI traffic number in GA4 is a floor, not a total. It is worth saying this out loud in the meeting, before someone draws conclusions about growth or decline from a base whose definition changes every quarter.

To reduce the gap in direct traffic, the way is to look at behavior inside your own website: which pages the person visited, in what sequence and how often, regardless of where they came from. Laiki's Lead Tracking, now in Beta, exists for this layer, and it complements GA4 instead of replacing it.

Frequently asked questions

Do I need to configure anything to see AI traffic in GA4?

For the native AI Assistant channel, no: it is automatic and already in the properties. What needs configuration is the custom group, to cover the platforms outside the official list and recover the history before May 2026.

My AI channel is empty. Is it a configuration error?

It may be the priority order, with the rule below Referral. Check that first. If the order is right, it is also possible that the website simply did not receive sessions with a recognized referrer in the period.

Can I separate who arrived through AI and bought?

You can, as long as the source is preserved all the way to the sale. The channel answers where the session came from; linking that to what became a customer depends on the source following the lead to the CRM.