How to track ChatGPT and AI assistant traffic in Google Analytics 4

In Google Analytics 4, visits from ChatGPT usually show up with chatgpt.com as the source, filed under the Referral channel where they are easy to miss. A custom “AI assistants” channel puts ChatGPT, Perplexity, Gemini, Claude and Copilot visits in one row, but a large share of AI clicks still arrive as Direct, so treat the GA4 number as a floor rather than a full count.

Last updated 20 October 2026 · Written by GPT Visibility

The short answer

Find ChatGPT today: Reports, then Acquisition, then Traffic acquisition, then switch the table to Session source / medium and search for chatgpt.
See every AI assistant together: build a custom channel group with an “AI assistants” channel and place it above Referral.
See which pages AI sends people to: make an Exploration with Landing page as rows, filtered to AI sources.
Annotate 8 to 16 October 2026, when a ChatGPT bug pushed most of its visits into Direct.
Add a second count that doesn’t rely on tags: a “How did you hear about us?” option for ChatGPT or AI assistants, and your server logs.

How ChatGPT visits are labelled

OpenAI’s publisher FAQ says ChatGPT automatically adds the parameter utm_source=chatgpt.com to referral URLs from ChatGPT search results, so that sites can track the traffic in tools such as Google Analytics. GA4 reads that tag, which is why ChatGPT clicks usually show chatgpt.com as their session source even when the browser sends no referrer. Some properties also show chat.openai.com, so search for both.

The tag only appears on links ChatGPT shows in an answer. A visitor who reads your name in an answer and then types your address, searches Google for you or rings you never appears as ChatGPT in GA4 at all.

Step 1: Find ChatGPT in your current reports

In GA4 open Reports, then Acquisition, then Traffic acquisition.
Above the table, change the dimension from Session primary channel group to Session source / medium.
Type chatgpt in the table’s search box, then try openai, perplexity, gemini, claude and copilot.
Write down every exact source string your property shows. Those are what your channel rule must match.

Step 2: Build an “AI assistants” channel

Google’s own help page on custom channel groups includes an AI assistants example. In short:

Go to Admin, then Data display, then Channel groups, and click Create new channel group. This starts as a copy of the default group. You need Editor access or above.
Click Add new channel, name it AI assistants, and add a condition on Source that matches regex.
Click Reorder and drag AI assistants above Referral. GA4 puts each visit in the first channel it matches, so if Referral sits higher it will keep taking these visits.
Save the group, then pick it as the dimension in the Traffic acquisition or User acquisition report.

Google’s example regex is deliberately broad: its first part matches any source containing the letters “ai”, which could also catch unrelated sites such as email services. A tighter starting point, which you should adjust to the source strings you found in Step 1, is:

chatgpt\.com|chat\.openai\.com|perplexity\.ai|gemini\.google\.com|claude\.ai|copilot\.microsoft\.com

Google says custom channel groups can be applied to your reports retroactively, so you can look back at past months straight away. Standard GA4 properties allow two custom channel groups on top of the default one.

Step 3: See which pages AI assistants send people to

Open Explore and start a blank exploration. Add Landing page + query string and Session source as dimensions, and Sessions and Key events as metrics. Put Landing page in rows, Sessions and Key events in values, and filter Session source with the same regex. The pages that come top are the ones AI assistants already cite. Keep their prices, services, areas and contact details accurate, because that is what visitors arrive expecting.

Why so many AI visits still land in Direct

GA4 files a visit as Direct when it has no tag and no referrer. AI clicks lose both more often than you might expect:

Copied links. Someone copies your address out of an answer and pastes it into a new tab.
Apps. According to Adobe’s Cedric Huesler, as reported by PromptMarketing, most ChatGPT clicks arrive without a referrer and the ChatGPT phone app never sent one, so the tag is doing most of the work.
Gemini. Search Engine Journal reported on 1 October 2026 that Gemini had started adding UTM tags to some links. Google hasn’t documented when or with what values, so check what actually arrives.
Google’s own AI answers. Clicks from AI Overviews and AI Mode are counted as normal Google search traffic, so they sit in Organic Search, not in your AI channel.

The October 2026 ChatGPT tagging bug

From about 8 October 2026, when GPT-6 reached free users, links in ChatGPT answers opened without the utm_source=chatgpt.com tag and without a referrer, so analytics filed those visits as Direct. PromptMarketing’s weekly round-up, citing Search Engine Roundtable and Search Engine Journal, reports that OpenAI confirmed a bug to Huesler on 14 October and began a fix on 15 October. Profound measured tagged links back at about 99% on 16 October at 06:30 UTC.

What to do about it:

Add a GA4 annotation for 8 to 16 October 2026 so nobody reads the dip as lost demand, or the recovery as growth.
If Direct rose over the same days ChatGPT fell, that is the same visitors under a different label.
Compare like with like: weeks before 8 October against weeks after 16 October.

Add a count that doesn’t depend on tags

Ask people. Add “ChatGPT or another AI assistant” to your “How did you hear about us?” field on enquiry and booking forms, and ask on the phone.
Check server or CDN logs for requests carrying utm_source=chatgpt.com or a chatgpt.com referrer. Leave out OpenAI’s own fetchers such as ChatGPT-User, which are robots reading your page for an answer, not people.
Track whether you’re named at all. Visits only happen after an assistant mentions you. Our guide on how to check if ChatGPT recommends your business sets out a repeatable test.

Common mistakes

Leaving the AI assistants channel below Referral, so it stays empty.
Using a regex so broad that it pulls in unrelated sources.
Reading the 8 to 16 October 2026 dip as AI sending fewer customers.
Treating the GA4 number as the whole story when many AI-driven visitors arrive as Direct or branded Google searches.
Blocking AI crawlers by accident, then wondering why nothing arrives. See our AI crawler guide.

Frequently asked questions

Where does ChatGPT traffic show up in Google Analytics 4?

Open Reports, then Acquisition, then Traffic acquisition, and change the table’s dimension to Session source / medium. Visits from ChatGPT usually appear with chatgpt.com as the source, because OpenAI says ChatGPT adds utm_source=chatgpt.com to referral links from its search results.

Why does my ChatGPT traffic show as Direct?

GA4 files a visit as Direct when it arrives with no tracking tag and no referrer. That happens when someone copies a link out of an answer, when the ChatGPT phone app opens a link, and it happened to most ChatGPT links between about 8 and 16 October 2026 because of a bug that OpenAI has since fixed.

Did ChatGPT stop adding utm_source=chatgpt.com?

No. Links in ChatGPT answers lost the tag from about 8 October 2026, and OpenAI confirmed it was a bug. A fix started on 15 October and Profound measured tagged links back at about 99% on 16 October.

How do I see all AI assistant traffic in one place in GA4?

Create a custom channel group under Admin, Data display, Channel groups. Add a channel called AI assistants whose source matches a regex listing the assistants’ domains, then move it above Referral so GA4 counts those visits there first. Google says custom channel groups apply to your reports retroactively.

Does Gemini traffic have a UTM tag?

Search Engine Journal reported on 1 October 2026 that Gemini had started adding UTM parameters to some links, and Google’s John Mueller said he could see it too. Google hasn’t documented when the tags are added or their exact values, so check what actually arrives in your reports.

Is GA4 counting every visit from ChatGPT?

No. GA4 only counts a visit as ChatGPT when it carries the tag or a chatgpt.com referrer, so the real number is usually higher than the report shows. A “How did you hear about us?” question and your server logs help fill the gap.