How to Track ChatGPT Traffic in GA4 After the October UTM Bug

To track ChatGPT traffic in GA4, start with the built-in AI Assistant channel, then add a custom channel group and a Direct-traffic check as a backup. The backup matters: in mid-October 2026, ChatGPT links briefly stopped carrying their utm_source tag, and analysts saw visits move into Direct until tagging was reported back on 15 October.

What happened to ChatGPT traffic in October 2026?

On 14 October 2026, Search Engine Roundtable reported that OpenAI appeared to have removed the UTM parameters it adds to links in ChatGPT answers. The change seemed to start with the release of GPT-6, about a week earlier. Without a tag and without a referrer, analytics tools had nothing to tell them where the click came from. As Adobe’s Cedric Huesler put it on LinkedIn: “There’s no tag and no referrer, so your analytics files the visit under direct.”

Huesler looked at roughly 500 pages where ChatGPT had previously brought at least 5% of visits, and compared 9–13 October with the previous week:

Sébastien Billard also reported on X a sharp drop in human ChatGPT traffic from 9 October. Search Engine Land stressed that the evidence pointed to an attribution problem rather than a confirmed fall in real visits, and advised reading referral, Direct and landing-page data together before drawing conclusions.

Then, on 15 October, Huesler updated his post: it was a bug, and ChatGPT was tagging its links with utm_source=chatgpt.com again. Search Engine Roundtable’s Barry Schwartz updated his article the same day. We found no public statement from OpenAI, so the “bug” explanation comes from these observers, not from OpenAI.

In our view, the lesson is bigger than one bug. ChatGPT has been adding UTM tags to its links for a while (Search Engine Roundtable reported in June 2025 that tagging was extended to the “More” links), and a lot of AI-traffic reporting depends on that one signal. If it disappears again, you want a setup that notices.

Why does ChatGPT traffic show up as Direct in GA4?

GA4 puts a session in Direct when the source is “(direct)” and the medium is “(none)” or “(not set)”, according to Google’s channel definitions. In plain terms: if a visit arrives with no campaign tag and no referrer, GA4 cannot say where it came from, so it calls it Direct. That is what happened during the October bug.

Even when ChatGPT’s tagging works, some AI visits can still end up in Direct. Search Engine Journal notes that traffic without a referrer header, for example from in-app browsers, some mobile apps, or links that people copy and paste, still lands in Direct.

Does GA4 have an AI Assistant channel?

Yes. In May 2026, Search Engine Journal reported that Google Analytics added “AI Assistant” to its default channel group, so AI visits no longer have to sit inside Referral. Google’s definitions page describes it as the channel for visitors arriving from sources like ChatGPT, Gemini, DeepSeek, Copilot or Grok. When the referrer matches Google’s list of AI assistants, the medium is set to “ai-assistant” and the campaign to “(ai-assistant)”.

Two limits are worth knowing. Google has not published the full list of AI sources it recognises, and the channel still depends on GA4 being able to identify the visit. It cannot recover a click that arrives with no tag and no referrer.

How to track ChatGPT traffic in GA4: step by step

1. Check the AI Assistant row. Open Reports, then Acquisition, then Traffic acquisition, and look at the default channel group. Set the date range to include 1–18 October 2026 so you can see whether your site was affected.
2. See the exact sources. Change the dimension to session source / medium and type “chatgpt” in the search box. Repeat for “perplexity”, “gemini” and “copilot” to see which assistants send you visitors.
3. Create a custom “AI assistants” channel group. In Admin, under Data display, open Channel groups and create a new group (you need the Editor role or above). Add a channel called “AI assistants” with a condition such as session source matches regex .*(chatgpt|openai|perplexity|gemini|copilot|claude|deepseek).*, then move it above Referral, because traffic lands in the first channel it matches (Google’s guide). Test the pattern against your own source list before relying on it. Google’s guide includes its own example AI regex you can start from.
4. Watch Direct on deep pages. Build an exploration with landing page and channel. Few people type a long blog URL by hand, so a sudden rise in Direct to deep article pages, at the same time as a fall in AI traffic, is a sign of an attribution problem.
5. Mark roughly 7–15 October 2026 (most visible 9–15 October). Add a note to your dashboards and monthly reports so nobody reads that week as a real drop in AI visibility.
6. Ask people how they found you. Add “AI assistant (ChatGPT, Gemini…)” as an option in your lead forms and WhatsApp intake questions. Self-reported answers catch visits that analytics misses.

AI Assistant channel vs custom channel group: which should you use?

In our view, use both: the built-in channel for everyday reporting, and a custom group when you need to control exactly which tools are counted or compare them side by side.

How should businesses in Lebanon and the Gulf read AI traffic?

In our experience, for most small and mid-sized sites AI assistants still send far fewer visits than Google Search, so a change of a few hundred sessions can look dramatic in percentage terms. In our view, the right question is not “did AI traffic drop?” but “did enquiries, sign-ups and WhatsApp conversations drop?” If they held steady while AI traffic fell and Direct rose, you were probably looking at a tracking issue. Measure the business result first, as we explain in our guide to measuring marketing campaign success and in KPIs vs key metrics.

Tracking also only tells you what already happened. To earn more visits from ChatGPT and other assistants, your pages need clear, answer-first content that AI tools can quote. Our explainers on SEO vs AEO and AI in SEO cover how to do that, and if you advertise there too, see ChatGPT visual ads.

What to do now

• Open Traffic acquisition and check the AI Assistant row for 7–15 October 2026.
• Compare Direct traffic to your deep article pages for the same dates and the weeks around them.
• Create a custom “AI assistants” channel group and place it above Referral.
• Note the October bug in your dashboards and client reports.
• Add an “AI assistant” option to “How did you hear about us?” in forms and WhatsApp.
• Re-check monthly: AI tools change how they link, and tracking can break again without warning.

Frequently asked questions

How do I see ChatGPT traffic in GA4?

Open the Traffic acquisition report and look for the AI Assistant row in the default channel group. For more detail, switch the dimension to session source / medium and search for “chatgpt”. If you want full control over which AI tools are counted, create a custom “AI assistants” channel group in Admin.

Why did my ChatGPT traffic drop in October 2026?

From around the GPT-6 release in early October, ChatGPT links appeared to lose both their UTM tag and their referrer, so analytics tools filed those visits under Direct. In one dataset of about 500 pages, ChatGPT visits fell by roughly 31,000 a day between 9 and 13 October while Direct rose by roughly 26,000 a day.

Is the ChatGPT UTM problem fixed?

On 15 October 2026, Adobe’s Cedric Huesler said it was a bug and that ChatGPT was tagging its links with utm_source=chatgpt.com again, and Search Engine Roundtable updated its report to match. We found no public statement from OpenAI, so keep watching your own data.

What is the AI Assistant channel in GA4?

It is a default channel that Google Analytics added in 2026 for visits from AI tools. Google describes it as covering sources like ChatGPT, Gemini, DeepSeek, Copilot or Grok. Sessions in it have the medium “ai-assistant”, and Google sets the campaign to “(ai-assistant)”.

Does the AI Assistant channel catch every visit from ChatGPT?

No. It relies on GA4 recognising the visit as coming from an AI assistant. Visits that arrive with no referrer, such as some in-app browser clicks or links that people copy and paste, still land in Direct.

Do I still need a custom channel group for AI traffic?

It is optional but useful. Google has not published the full list of sources in the AI Assistant channel, while a custom channel group counts exactly the sources your rule matches and, according to Google, can be applied to your reports retroactively (except for groups used in audiences). Standard GA4 properties can have two custom channel groups.

Can I move the misattributed October visits back to ChatGPT?

Not reliably. Channel rules work on the source and medium GA4 recorded, and those visits were recorded as (direct) / (none), with nothing that identifies ChatGPT. The practical approach is to note the dates in your reports and compare Direct traffic to deep article pages with the weeks before and after.

Sources

• Search Engine Roundtable: OpenAI Drops UTM Parameters From ChatGPT Results (GPT-6), 14 October 2026, updated 15 October 2026
• Search Engine Land: ChatGPT appears to drop UTM tracking, making AI referral traffic harder to measure, 15 October 2026
• Search Engine Roundtable: OpenAI ChatGPT analytics update (UTM tags on “More” links), 16 June 2025
• Search Engine Journal: Google Analytics Adds AI Assistant As Default Channel Group, 14 May 2026
• Google Analytics Help: Traffic-source dimensions and default channel group definitions (accessed 19 October 2026)
• Google Analytics Help: Custom channel groups (accessed 19 October 2026)

Status as reported on 19 October 2026. We found no public statement from OpenAI on the October tagging change, and Google may update its list of AI assistant sources at any time, so check your own reports.

Written by the Gradezilla team · Reviewed by Bashar Amin