Where AI visits land in GA4 today
GA4 groups traffic into default channels. One of them is AI Assistant, so visits from chatgpt.com are normally reported there and not under Direct. "Normally" matters: see the tagging gap below. We checked it on Adviora's own property. In the 28 days from 17 September to 14 October 2026, the AI Assistant row looked like this:
| Channel | Sessions | Engaged sessions | Engagement rate | Average engagement time |
|---|---|---|---|---|
| AI Assistant | 3 | 2 | 66.7% | 2m 17s |
In the source / medium view, those sessions show as chatgpt.com / ai-assistant. Three sessions is a small number, and we are not offering it as a result. The point of this page is the method. Check Google's Analytics release notes for when the channel was added to your property before you rely on it.
Step 1. Read the built-in AI Assistant channel
- Open Reports, then Acquisition, then Traffic acquisition.
- Change the primary dimension to Session default channel group.
- Find AI Assistant in the list.
- Add Session source / medium as a secondary dimension.
Which engines the channel includes is set by Google. Read the current list on Google's default channel group definitions page and note the date you checked. Do not assume it covers every engine you care about.
Step 2. Fallback: a custom channel group for engines the default misses
Do this only when your property predates the change, or an engine's hostname is missing from the default definition. Here is the draft regex Adviora uses as a starting point. It is a draft to test, never a finished rule:
chatgpt.com|chat.openai.com|perplexity.ai|claude.ai|gemini.google.com|copilot.microsoft.com|chat.deepseek.com|chat.mistral.aiTest it against the real referrer hostnames in your own GA4 before you trust it. Put it in a test channel group first and compare the result with what the default channel reports.
Step 3. Keep UTM-tagged links from breaking the channel
OpenAI documents that ChatGPT referral URLs carry utm_source=chatgpt.com. A UTM source overrides the referrer, so your channel rule has to match the utm_source value too, not only the hostname. Adviora's own fix list includes adding UTM tags for Smartlead and ChatGPT, which is the same lesson from the other side: tag your own links so they do not get misfiled.
The 8 to 15 October 2026 ChatGPT referral gap
Between 8 and 15 October 2026, practitioners reported ChatGPT sending visitors with no UTM tag and no referrer. GA4 had nothing to read, so those visits were counted as Direct. LinkedIn commenter Allen G. described the gap and said referrals were back by 16 October (LinkedIn research, 20 October 2026; link with the SEO lead). We treat it as sentiment from one source, not a measured fact about every site.
What to do about it:
- Annotate 8 to 15 October 2026 in GA4 and in your weekly report as a ChatGPT referral-tagging gap, so a dip in the AI Assistant row is not read as a drop in influence.
- Do not back-fill the Direct row by guesswork. Note that Direct was inflated for the window, and leave the numbers as recorded.
- Compare against the previous 28 days only after you have noted the gap, because the comparison period is affected.
GA4 versus server and CDN logs
GA4 counts visits where its tag runs and the visitor accepts it. Server and CDN logs record every request, including visitors who block scripts and automated fetches by AI crawlers and user-triggered agents. The two will not match, and neither is the "right" one. GA4 tells you about people who arrived and acted. Logs tell you what was requested. A request from ChatGPT-User or OAI-SearchBot in your logs is a fetch, not a visit, so keep it out of your session count.
When a gap opens between them, as it did in the October window, check the log for requests with utm_source=chatgpt.com in the URL and compare the count by day. The ability to do this depends on what your host or CDN keeps, so confirm retention before you promise a reader a comparison. The AI crawler access check covers reading the logs by user agent.
Step 4. Connect AI visits to lead events
Add a key-event column to the channel row. For Adviora that means Sign_Up, Audit_Report_Email_Verified and, once it is live, generate_lead. Be honest about what the number means. The 2 key events on our AI Assistant row sit in a property where about half of all key events were pricing-page views, so the count is not two leads. Clean up the key events first, then read the column.
What referral numbers cannot tell you
Referrals are a floor. An answer that names you without a link sends no session. In Adviora's October 2026 panel, most AI answers cited third-party listicles, not vendor sites, so a brand can be influencing buyers with zero referral rows. For the mention and citation side, read AI share of voice: define the denominator. For influence that never shows up as a visit, add a "How did you hear about us?" field to your form and include "ChatGPT" as one of the answers (alongside other AI assistants, search, and word of mouth). Self-reported source is imperfect and people forget, but it catches the buyer who read a ChatGPT answer, typed your name into a browser, and landed in Direct. Report it beside the GA4 number, not instead of it. If you want the wider picture of AI search analytics, the methodology page explains how we measure AI visibility.
The report template
Copy this table into a GA4 Exploration or a spreadsheet:
| Channel | Source / medium | Sessions | Engaged sessions | Key events | Key event rate | Date range | Compared with previous 28 days |
|---|---|---|---|---|---|---|---|
| AI Assistant | chatgpt.com / ai-assistant | ||||||
| AI Assistant | |||||||
| Custom AI group (if used) |
Use the same date range every time and compare each period with the previous 28 days. Our own target for AI Assistant sessions by Day 60 is 15 per 28 days, from 3 today. That is a target, not a forecast.
What to fix first
- Check the channel exists and which engines it includes.
- Tag your own links with UTM parameters.
- Annotate the 8 to 15 October 2026 gap, and compare against logs where you have them.
- Add the "How did you hear about us?" field with ChatGPT as an option.
- Wire the lead event, and clean up key events that count pricing-page views.
Then see what the rest of your site needs with the free AI visibility checker.