How to Track AI Traffic in GA4: ChatGPT, Perplexity, Gemini and More

Short answer

Since May 2026, GA4's default channel group has an AI Assistant channel for visits from sources such as ChatGPT, Gemini, Copilot and Grok. Open Reports, then Acquisition, then Traffic acquisition, and look for the AI Assistant row under Session default channel group. For control over which sources count, or to cover older data, build a custom channel group with a regex and move it above Referral. Clicks from Google AI Overviews and AI Mode are not in that channel: GA4 counts them as Organic Search.

Key takeaways

GA4 added an AI Assistant channel to its default channel group in May 2026. It assigns the medium ai-assistant when the referrer is a recognized AI assistant.
Google AI Overviews and AI Mode are excluded from it. GA4 counts those clicks as Organic Search, and Search Console's generative AI report shows impressions.
OpenAI adds utm_source=chatgpt.com to the links in ChatGPT search results, so ChatGPT referrals are identifiable.
GA4 can't show what AI crawlers read on your site, or visits that arrive without a referrer. Those need server logs and proxy signals.

Where does AI traffic show up in GA4?

Until recently, a click from ChatGPT or Perplexity landed in the Referral channel with every other site that links to you. In its release notes for May 13, 2026, Google announced a dedicated way to measure traffic from AI assistants: GA4 now assigns the medium ai-assistant when the referrer matches a recognized AI assistant, groups those visits in a new AI Assistant channel in the default channel group, and labels the campaign (ai-assistant).

Google's channel documentation describes the channel as visits from sources like ChatGPT, Gemini, Deepseek, Copilot or Grok, and its release note also names Claude. Perplexity isn't in either list, so check where it lands in your property. The channel excludes Google's AI Overviews and AI Mode: those clicks are part of Organic Search.

How do you check it?

Open Reports > Acquisition > Traffic acquisition and set the dimension to Session default channel group if it isn't already.
Look for the AI Assistant row. Add Session source / medium as a secondary dimension to see which assistants send visits.
Compare sessions, engaged sessions and key events with other channels.
Look at which landing pages AI visits start on. Those are the pages AI sends people to.

Google's release note doesn't say whether older data is reclassified. If you want history, build a custom channel group, which Google says can be applied to your reports retroactively.

How do you build a custom AI channel group?

Use this when you want control over the list of sources, such as including Perplexity, or a view that covers older data.

In Admin, under Data display, click Channel groups, then Create new channel group. You need Editor access or above.
Add a new channel named "AI assistants".
Set the condition to Source matches regex and enter:

.*(chatgpt|openai|perplexity|claude\.ai|gemini\.google|copilot\.microsoft|grok\.com).*

Reorder the channels so AI assistants sits above Referral. GA4 puts traffic in the first channel whose definition it matches, so a channel below Referral never gets the visits.
Save the group, then pick it as the dimension in Acquisition reports or Explorations.

Google's own documentation has an AI assistants example with a longer regex and the same advice on ordering. Update the pattern when you add sources. Test it in an Exploration by listing source values and checking that nothing unrelated matches. The free AI Traffic Tracker for GA4 generates the regex and steps for the assistants you choose.

What does each source look like?

Source	Typical referrer host	Notes
ChatGPT	chatgpt.com	OpenAI adds utm_source=chatgpt.com to referral URLs from ChatGPT search results
Perplexity	perplexity.ai	Not named in Google's channel descriptions
Gemini	gemini.google.com	Distinct from Google AI Overviews and AI Mode
Claude	claude.ai	Named in Google's release note
Copilot	copilot.microsoft.com	Named in Google's channel description
Google AI Overviews and AI Mode	google / organic	Counted as Organic Search, so they can't be separated

What can GA4 not tell you?

AI Overviews and AI Mode clicks. They sit inside Organic Search. For Google's AI features, use the Generative AI performance report in Search Console, which shows how many times your pages appeared by page, country, device and date. Google had rolled it out to all websites worldwide as of August 31, 2026.
Visits with no referrer. Any visit that arrives without a referrer or campaign tags is Direct in GA4.
AI crawler reads. Analytics tags measure people, and AI crawlers don't execute them, as Citepoint's developer docs note. To see which pages ChatGPT's and Claude's crawlers read, use server logs or forward requests from your server. Citepoint's docs have snippets for Next.js and Cloudflare Workers that do this.
Influence without a click. A buyer may read an AI answer, then search your name later. Microsoft Advertising suggests watching branded search, direct and returning traffic and assisted conversions as proxy signals for AI influence.
Citations in Copilot. Those are in Bing Webmaster Tools' AI Performance report. See how Microsoft Copilot chooses sources.

What mistakes skew the numbers?

A regex that's too loose. A pattern that matches "ai" anywhere in a source will pull in unrelated sites. List the assistants you mean.
The wrong order. If Referral sits above your AI channel in a custom group, it claims the visits first.
Mixing Google's AI features with assistants. AI Overviews and AI Mode are Organic Search, and the AI Assistant channel excludes them. Read the two separately.
Reading small numbers as a trend. AI referrals can be a small share of sessions. Compare monthly totals before drawing conclusions.
Forgetting that GA4 starts when the tag loads. Pages without the tag, or visitors who decline measurement, are missing from every report.

What should you report each month?

Measure	Where to find it
Sessions and key events from the AI Assistant channel	GA4 Traffic acquisition
Landing pages for AI visits	GA4, with the channel as a filter
Impressions in AI Overviews and AI Mode	Search Console, Generative AI performance report
How often AI names or cites you	An AI visibility tool, or your own repeated checks. See how to measure AI visibility
Crawler reads	Server logs

Expect traffic to lag behind visibility. Citepoint tracks visibility across six engines, and its Authority and Agency plans add revenue from AI visits, with sign-ups and revenue by AI source, through a read-only Google Analytics connection.

Frequently asked questions

Does GA4 track visits from Google AI Overviews?

Not separately. Google's channel documentation says Organic Search includes Google's AI Overviews and AI Mode, and that the AI Assistant channel excludes them. Use Search Console's Generative AI performance report for impressions.

Why does ChatGPT traffic show up as chatgpt.com?

OpenAI says ChatGPT automatically includes the parameter utm_source=chatgpt.com in referral URLs from its search results, so GA4 can record the source and you can analyze that traffic.

Do I still need a custom channel group now that GA4 has an AI Assistant channel?

Not necessarily. The default channel covers sources Google recognizes. A custom group lets you choose the sources, such as adding Perplexity if it doesn't land where you expect, and Google says custom channel groups can be applied retroactively.

Can GA4 show which pages AI crawlers read?

No. Crawlers don't run analytics tags. Use server logs or forward crawler requests from your server to a tool that counts them.

Why must the AI channel sit above Referral?

GA4 assigns traffic to the first channel in the list whose definition it matches. If Referral comes first, it claims the visit before the AI channel can.