The AI Assistant channel in GA4: what it counts and what it misses

Google Analytics 4 (GA4) now sorts visits from AI assistants into their own channel, named AI Assistant. Google added it on May 13, 2026. It counts visits that arrive with a referrer Google recognizes as an AI assistant, such as ChatGPT or Gemini. It does not count visits from Google's own AI Overviews and AI Mode, which GA4 files under Organic Search.

A channel is a bucket GA4 uses to group visits by how people arrived: Organic Search, Direct, Referral, Paid Search and so on. Before this change, the default channel group had no bucket for AI assistants. Under GA4's channel rules we would expect such a visit, when it carried a referrer, to fall under Referral with every other website that links to you, unless you had built a custom channel for it. That is our reading of the rules, not a statement or a measurement from Google.

The new channel is a convenience, and you should use it. It is also an undercount, for reasons that are built into how it works. This guide explains the definition, where to find the channel, how to report on it, and what it can't see.

What Google's definition says

Google's default channel group page gives both a description and a rule. The description is the sentence quoted above. The rule is: "The medium exactly matches 'ai-assistant'. The medium is set to 'ai-assistant' and the campaign is set to '(ai-assistant)' if the referrer matches a list of AI Assistants."

Three terms need a plain definition.

• Referrer. When someone follows a link, their browser can tell the destination site which page they came from. That piece of information is the referrer.
• Medium. GA4's label for the general type of traffic, such as organic, referral or email.
• Campaign. GA4's label for a named marketing effort. Here Google fills it in automatically.

Put together: when a visit arrives and the referrer is on Google's list, GA4 stamps the visit with the medium "ai-assistant," and anything with that medium goes into the AI Assistant channel. The whole thing depends on a referrer being present and being on the list.

What changed on May 13, 2026

Google's release notes carry an entry under the heading "New AI Assistant traffic measurement." It says Analytics "now provides a dedicated way to measure and analyze traffic originating from popular AI assistants" and lists three changes: a new "ai-assistant" medium, the "AI Assistant" channel, and the "(ai-assistant)" campaign name.

Google doesn't state whether visits recorded before May 13, 2026, were reclassified. If you compare this year with last year, the channel may be empty or thin before that date, so don't read a jump as growth.

A second change followed on June 11, 2026: a "Source Group" field that Google says "includes built-in grouping for emerging traffic sources like ChatGPT (OpenAI) and Perplexity." Google describes it as for cross-channel reporting in the advertising section, so it is a separate feature from the channel.

Which assistants are counted

This is less clear than it looks. Google's two pages give different examples.

Both lists are introduced with "like," so they are examples, not the full list. Google doesn't publish the referrers it matches. It offers a downloadable list of sources for other channels, and as of October 2026 that list has categories for search, social, shopping and video only.

The practical consequence: don't assume a particular assistant is included because it is well known. Check your own data. If you see visits from an assistant's domain sitting in Referral instead of AI Assistant, Google's list may not cover it, and a custom channel group (below) is the fix.

What the channel leaves out

Google's AI Overviews and AI Mode

The definition says so directly, and Google's definition of Organic Search confirms where those visits go: "Organic Search is the channel by which users arrive at your site/app via non-ad links in organic-search results, including Google's AI Overviews and AI Mode."

So a visitor who clicks a link in an AI Overview looks, in GA4, like any other Google organic visitor. GA4's default channels give you no separate line for them. For Google's AI features, the nearest first-party data is impressions in Search Console, which we cover in how to read the Generative AI performance report.

Visits that arrive without a referrer

Google's documentation on how traffic sources are processed says: "A session is processed as direct traffic when no information about the referral source is available." A visit from an AI answer that reaches you with no referrer and no campaign tags can't be matched to any list. It is counted as Direct.

Google's page on direct traffic lists general reasons source information goes missing, including redirects, URL shorteners and ad blockers. It doesn't mention AI assistants or their mobile apps by name. And as of October 2026, we could not find a statement from OpenAI, Anthropic, Perplexity, Microsoft or Google that an assistant guarantees a referrer on the links in its answers. We found no vendor documentation on when a referrer is passed, so don't assume one.

People who never click

Someone asks an assistant for a recommendation, reads your name, and types your address into a browser the next day, or searches for you on Google. GA4 records a Direct or Organic Search visit. The AI answer did the work and gets no credit. No analytics setting fixes this.

Visits that don't run your tracking

Google notes that Analytics tracks "traffic only from users who have enabled JavaScript in their browser." An automated fetcher that reads your page on a user's behalf and doesn't run your analytics script leaves nothing in GA4, so it won't appear in this channel. Server logs are the place to look for those, as explained in how to verify real AI bots in your server logs.

Where to find the channel

Google documents the path to the Traffic acquisition report like this.

1. "From the left menu, select Reports."
2. "On the left, select Acquisition > Traffic acquisition."
3. The table's default dimension is "Session default channel grouping." Look for the AI Assistant row.
4. If the list is long, use the search bar above the table.

If the report isn't in your menu, Google says "it may have been removed or isn't in your default view. Editors (and above) can add it back to the left navigation."

The default channels appear under three dimensions, and they answer different questions.

Traffic acquisition shows new and returning users. The User acquisition report shows where new users came from. For a monthly count of AI visits, use the session version and stay with it.

Building a report around it

Google says these dimensions appear "in the Acquisition reports, the Advertising section, and if you include them in custom reports." We found no Google help page describing a ready-made template for AI traffic, so plan to build your own view. A useful one answers four questions.

• How many sessions? The AI Assistant row, month over month.
• From which sources? Look at "Session source / medium" for those sessions. The medium will read "ai-assistant." The source shows where each visit came from.
• To which pages? The landing pages show what assistants are linking to. Those pages are worth keeping accurate and current.
• With what result? Key events, such as form submissions or calls, tied to those sessions.

Existing guides on this site go further on setup: how to track AI traffic in GA4 and how to build an AI traffic dashboard.

When to build a custom channel group

Google is plain that "Default channel groups can't be edited in Google Analytics." If the default list misses an assistant your customers use, you need your own group. Google's custom channel groups page gives the steps, and you need the Editor role or above.

1. "In Admin, under Data display, click Channel groups."
2. "Click Create new channel group to start with a copy of the default group."
3. Add or edit a channel and set its conditions, for example on Source.
4. "Click Reorder and drag to reorder the list."
5. Save the group.

Order matters, because "Traffic is included in the first channel whose definition it matches given the current order of channels in the group." Google's own example on that page tells you to place an AI assistants channel above Referrals.

Some limits to know: a standard property can have 2 custom groups in addition to the default, and a 360 property 5, with up to 50 channels in each. Custom groups "can be applied to your reports retroactively." They aren't available in the Key events paths report or in the BigQuery export.

Google's page still carries an example recipe for an AI assistants channel built on a pattern match, naming ChatGPT, Gemini, Microsoft Copilot, Claude and Perplexity as popular assistants. Read the pattern before you copy it, and test it against the sources in your own reports. Google itself says "You should update your regex expression if URLs or the list of assistants you wish to measure change."

How to use the number without overreading it

• Call it a floor. Label it "AI-referred sessions we can identify," not "AI traffic."
• Watch the trend. The direction over several months is more reliable than any one month's count.
• Keep the definition fixed. If you switch from the default channel to a custom group, note the date. The two won't match.
• Ask people. A "How did you hear about us?" field on your forms catches buyers analytics files under Direct.
• Pair it with visibility checks. A fixed list of test questions shows whether you appear in answers at all. See how to build a prompt set.

If you are using this number to justify spending, how to build the business case for GEO shows how to combine it with other signals.

Conclusion

The AI Assistant channel gives you a free, automatic count of visits GA4 can tie to an AI assistant. It leaves out Google's AI Overviews and AI Mode by definition, and it misses any visit that arrives without a referrer or after a delay. Use it as a trend line, add a custom channel group if Google's unpublished list doesn't match your audience, and back it up with what customers tell you. If you'd like help reading what your data shows, eSEOspace offers a free GEO audit of your website structure and visibility. More guides are in our GEO and AEO Guide.

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