How to track AI traffic in GA4: the 2026 setup

To track AI traffic in GA4 in 2026, start with the AI Assistant channel Google added on May 13, 2026 to the default channel group, the rules GA4 uses to sort visits, then add a custom channel group that matches the main AI assistants' domains with one tested regular expression. Together they put ChatGPT, Perplexity, Gemini, Copilot and Claude visits on one line, page by page. Neither sees clicks from Google's AI Overviews and AI Mode, which GA4 counts as Organic Search.

If your ChatGPT visits dipped in mid-October 2026, that was a tracking bug, explained in our post on ChatGPT traffic showing as Direct.

Does GA4 have a built-in AI channel in 2026?

Yes. Since May 13, 2026, GA4 gives visits from a recognised AI assistant the medium ai-assistant and the campaign (ai-assistant), and files them under a new AI Assistant channel in the default channel group, with no setup, according to Google's release notes.

A channel group is the set of rules GA4 uses to sort visits into channels such as Organic Search, Referral and Direct. What the new channel covers, from Google's default channel group definitions:

• It names ChatGPT, Gemini, Deepseek, Copilot and Grok as examples; the May release note named ChatGPT, Gemini and Claude. Google hasn't published the full list.
• It works from the referrer, the address a browser passes on when someone clicks a link. A visit with no referrer and no tag stays in Direct.
• It excludes Google's AI Overviews and AI Mode. Google's definition of Organic Search says it includes them.
• The default group can't be edited, so you can't add an assistant yourself.

Perplexity isn't named in Google's text, but it seems to be recognised: a July 2026 report by Ann Smarty in Practical Ecommerce showed chatgpt.com, gemini.google.com, perplexity.ai and claude.ai, all with the ai-assistant medium.

Google's note doesn't say older visits were relabelled. A separate Source group dimension, added in June 2026, groups ChatGPT and Perplexity for advertising reports. The built-in channel is a good start; a custom channel group fills the gaps and reaches back before May.

Which referrer domains do AI assistants send?

Each AI assistant's web app passes its own domain to your site as the referrer when someone clicks a link, unless that link is set to withhold it. So a ChatGPT click shows the source chatgpt.com in GA4. The main assistants in October 2026:

Each domain passed two checks. The referrer policy each web app sets, which tells the browser what to pass on, was read on October 25, 2026: all twelve allow at least their domain through. And every domain is on the open list Matomo keeps for its own AI Assistants channel, last updated in July 2026.

chat.openai.com now redirects to chatgpt.com, so it only matters for older data. openai.com is left out on purpose: visits from OpenAI's own site aren't clicks from ChatGPT answers.

The AI referral traffic regex for GA4

The AI referral regex below matches every source in the table, with or without a subdomain such as www, and no lookalikes. Paste it as one line wherever GA4 or Looker Studio asks for a regex on Source or Session source:

^(.*\.)?(chatgpt\.com|chat\.openai\.com|perplexity\.ai|gemini\.google\.com|copilot\.microsoft\.com|claude\.ai|chat\.deepseek\.com|grok\.com|meta\.ai|chat\.mistral\.ai|you\.com|duck\.ai|chat\.qwen\.ai)$

The pattern was tested against 16 spellings of AI sources and 28 that aren't AI assistants, including google.com, mail.google.com, openai.com, gemini.com, copilot.github.com and lookalikes such as chatgpt.com.example.net. It matched all 16 and none of the 28. The ^ and $ anchors make it behave the same whether a tool reads a regex as a full or a partial match.

Google's own help page offers an example regex for an AI channel, and it is broad. In the same test it missed DeepSeek, Grok and You.com, and counted gemini.com, a crypto exchange, otter.ai, a meeting notes app, and most of the lookalikes.

Matomo's list gained Grok, DeepSeek, Qwen and Duck.ai between August 2025 and July 2026, so check yours every quarter. A new AI domain that shows up under Referral goes inside the brackets, after a |, with a backslash before each dot.

How to create a GA4 custom channel group for AI

A GA4 custom channel group for AI takes about five minutes: copy the default group, add an AI channel that matches the regex on Source, and move it above Referral. You need the Editor role on the property, according to Google's guide to custom channel groups.

1. In GA4, open Admin and, under Data display, choose Channel groups.
2. Click Create new channel group, which starts as a copy of the default group, and name it "Channels with AI".
3. Click Add new channel and name it "AI assistants".
4. Click Add condition group, choose Source, then "matches regex", and paste the regex. Save the channel.
5. Click Reorder and drag "AI assistants" above Referral and above Google's AI Assistant channel. GA4 puts each visit in the first channel it matches. Click Apply.
6. Click Save group.
7. Optionally, make it your primary channel group on the same page. Google says that applies to future reporting only.

Keep Google's AI Assistant channel directly below yours. It catches assistants Google recognises that your pattern lacks: a visit there is your cue to add a domain. A custom group built before May 2026 was copied from the old default, so check that it has an AI rule at all.

Custom channel groups apply to reports retroactively, Google says, so your AI line includes visits from before May 2026. A standard property can have two custom groups of up to 50 channels each.

One more check: in Admin, open your web data stream, then Configure tag settings and List unwanted referrals. An AI domain on that list is not shown as a traffic source.

Where to see AI traffic in GA4 reports

AI traffic shows up under Reports, then Acquisition, then Traffic acquisition. Set the primary dimension to Session default channel group for Google's AI Assistant row, or to your custom group for your own. Add Session source as a secondary dimension to split it by assistant.

An exploration of AI landing pages

The most useful view shows which pages AI assistants send people to. An exploration, under Explore, is GA4's build-your-own report:

1. Open Explore and start a blank exploration.
2. Add the dimensions Landing page + query string and Session source, and the metrics Sessions, Engaged sessions and Key events.
3. Put the landing page in Rows and the metrics in Values. Session source in Columns gives one column per assistant.
4. Add a filter: Session source, matches regex, with the pattern above.
5. Set the date range to the last 90 days and sort by Sessions.

Explorations only reach back as far as your data retention setting, 2 or 14 months on a standard property. Standard reports aren't limited by it, Google says.

The pages at the top are the ones AI tools chose to link, so keep their facts, prices and dates current.

A Looker Studio view of AI traffic

For a report you can share, Looker Studio, Google's free dashboard tool, reads GA4 directly:

1. Create a report and add your GA4 property with the Google Analytics connector.
2. Add a table with the dimension Landing page + query string and the metrics Sessions, Engaged sessions and Key events.
3. Add a filter to the table: Include, Session source, RegExp Match, then the pattern.
4. Add a time series chart of Sessions with the same filter for the weekly trend.

The anchors mean the pattern works with RegExp Match or RegExp Contains. Since September 9, 2026, GA4 also has its own Dashboards, if you'd rather stay in one tool.

What GA4 still can't see

GA4 only recognises an AI visit when the click brings a referrer or a tag with it. Three gaps remain in 2026, and the regex closes only the third.

AI visits that arrive as Direct

An AI visit lands in Direct when neither a referrer nor a tag reaches your site. Search Engine Journal noted when the channel launched that this can happen with in-app browsers, mobile apps and copied links. For about a week in October 2026, the ChatGPT bug did the same to many links.

Visits recorded as Direct can't be relabelled. ChatGPT's tag rides in the link itself, so a tagged visit keeps its source even when the referrer is lost. And few people type the address of a deep page, so a rise in Direct visits to blog posts alongside rising AI referrals is a hint, not proof.

AI Overviews and AI Mode clicks counted as Google organic

Clicks from Google's AI Overviews and AI Mode count as Organic Search in GA4, mixed with ordinary Google results, as Google's channel definitions state. No regex can pull them apart. A click in Gemini on the web is different: it comes from gemini.google.com and lands in AI Assistant.

The closest measure is Search Console. Its generative AI performance reports, launched on June 3, 2026 and open to every site since August 31, show how often your pages appeared in AI features such as AI Overviews and AI Mode, by page, country, device and date, according to Google. Impressions are their only metric: no clicks.

Put a page's AI impressions next to its Organic Search sessions in GA4 to see whether being shown turns into visits. Google's October changes to AI answer links are in our post on the AI Mode links update, and getting cited in our AI Overviews guide.

utm_source=chatgpt.com and the (not set) medium

utm_source=chatgpt.com is a tag ChatGPT adds to the links it cites. In LLM Pulse's daily tracker, updated October 24, 2026, 96.55% of ChatGPT answers with citations on the latest day had at least one tagged link.

The tag sets the source but not the medium. Google's help says missing UTM parameters show as (not set), so a tagged visit can read chatgpt.com / (not set). When no channel rule matches a visit, GA4 calls it Unassigned. Google doesn't document whether its AI Assistant rule still catches a tagged visit like this. A channel matched on Source catches it either way.

How QuQi helps

GA4 counts clicks. It can't tell you how often ChatGPT, Perplexity, Gemini or Google's AI Overview named your business without a click, or named a competitor instead (see how to check whether ChatGPT mentions your brand).

QuQi's AI Visibility teammate runs that check every week. It asks those four the questions your buyers ask, records who is named instead of you, and turns each gap into a brief for the Copywriter. With Search Console connected, QuQi reads your search data too, and every batch runs in a chat you can open and step into.

Questions people ask