ChatGPT is sending you customers, and GA4 calls them Direct (Direct ≠ “typed it in”)
Chinmay Raibagkar · found ChatGPT hiding inside a Direct traffic spike🤖 with a floor-to-ceiling range builder, not a lecturePublished October 4, 2026
The 60-second version
- AI assistants now send buyers to deep pages, but app clicks and copied links arrive with no referrer and land in Direct.
- GA4’s AI Assistant channel and utm_source=chatgpt.com give you a floor; unexplained Direct growth to deep pages sets the ceiling.
- The fix: report a range, keep the AI domain list fresh, and add an AI option to “how did you hear about us?”.
The growth team notices something nobody planned: Direct traffic to deep pages is up 50% on the same months last year — and it isn't the homepage. The extra visits land on deep pages: a size guide, a "best for flat feet" comparison, a product most people have never heard of.
Nobody typed those URLs from memory. Customers are asking ChatGPT, Gemini or Claude "which running shoe should I buy for flat feet?", getting your product in the answer, and clicking through — often from an app that sends no referrer. GA4 sees a visit from nowhere and files it under Direct. Direct ≠ "typed it in"
AI assistants are becoming a real way people find products. Some of that traffic is now visible in GA4. A lot of it still isn't. The honest answer to "how much traffic do we get from AI?" is a range, and this post shows how to build one.
Three months of 'Direct' growth, explained
Three ways AI visitors arrive
When someone clicks from an AI assistant to your site, the visit can land in very different places in GA4 depending on where they clicked and how.
Your split will differ by audience and assistant. The pattern holds: some AI traffic is labelled, some is findable, and a large part hides in Direct.
Two recent changes help:
- GA4 now has an AI Assistant channel. Google added it to the default channel group in 2026. When GA4 recognises the referrer — ChatGPT, Gemini and Claude are named — it sets the medium to
ai-assistantand the channel to "AI Assistant". No setup needed. - ChatGPT tags many of its links. Links clicked from ChatGPT search results often carry
utm_source=chatgpt.com, so the source survives even when the referrer doesn't.
Neither helps when the click comes from a mobile app that strips the referrer, or when someone copies a link from the answer into their browser. Those visits arrive with no clue at all — and become Direct.
The floor: what GA4 can prove
Start with everything you can positively identify. In the GA4 interface, build a custom channel group with an "AI assistants" channel that matches the source against a list of AI domains, placed above Referral. In BigQuery, the same idea looks like this:
Treat this number as a floor: AI traffic is at least this much, never less. Keep the domain list up to date as new assistants appear.
The ceiling: Direct traffic that behaves like AI traffic
Some of the hidden traffic leaves fingerprints. AI assistants send people to specific deep pages — comparisons, guides, individual products — rather than the homepage people type from memory. So watch Direct sessions that land on deep pages, compared with a fair baseline (the same months last year, adjusted for overall growth).
Same period last year, adjusted for overall growth
More AI traffic may be hiding in Direct than you can see. Report the range, and add an AI option to your 'how did you hear about us?' question to narrow it.
The ceiling is an upper bound, not a measurement. Other things also grow Direct traffic to deep pages — offline campaigns, shared links in WhatsApp groups, press coverage. If you ran any of those, the ceiling overstates AI. That's exactly why the third step exists.
Ask the customer
Analytics can only guess where the hidden visitors came from. Customers can simply tell you. Add "ChatGPT or another AI assistant" as an option in your post-purchase or sign-up question "How did you hear about us?".
📈 Clicks with clues
Precise, but only for visits that carry a referrer or a tag. Blind to apps and copied links.
- Exact session counts
- Landing pages and conversions
- Misses most app traffic
🗣️ Remembered influence
Imprecise, but sees what tracking can't — including people who asked an AI, then searched for you by name later.
- Catches 'asked ChatGPT, then Googled the brand'
- Small samples, so read it as a share
- Pairs well with a range
If 6% of buyers name an AI tool but only 2% of tracked conversions come from the AI channel, lean towards the top of your range. More on mixing the two in self-reported attribution vs the pixel.
Your AI traffic routine once a month →
- Report a range, not a number — floor from the AI channel and tagged sources, ceiling from unexplained deep-page Direct growth.
- Keep the AI domain list current — add new assistants to your custom channel group and the SQL pattern as they appear.
- Track which pages AI sends people to — those pages are being quoted in answers. Keep their facts, prices and stock status accurate.
Quick gut-check
One question. If you get it, the whole post clicks. no regex required
GA4's AI Assistant channel shows 900 sessions a month. Direct traffic to product pages grew by 2,000 sessions over the same period, with no campaigns to explain it. What should you report?
Frequently asked questions
Does GA4 track ChatGPT traffic?
Partly. GA4 now has an AI Assistant default channel for recognised AI referrers such as ChatGPT, Gemini and Claude, and ChatGPT adds utm_source=chatgpt.com to many links. Visits from apps or copied links that carry no referrer still show up as Direct.
Why does AI traffic show up as Direct?
Many AI apps don't pass a referrer when someone taps a link, and people often copy a link from an answer into their browser. With no referrer and no campaign tag, GA4 has nothing to go on, so it classifies the visit as Direct.
How should I report AI referral traffic?
As a range. Use the AI channel and tagged sources as the floor, unexplained growth in Direct visits to deep pages as the ceiling, and a "how did you hear about us?" option for AI assistants to judge where in the range you are.
The summary
- People now find products by asking AI assistants, and click through to deep pages.
- GA4's AI Assistant channel and ChatGPT's link tags make part of that traffic visible.
- App clicks and copied links carry no referrer, so a large share still lands in Direct.
- Report a range: the visible floor, and a ceiling from unexplained deep-page Direct growth.
- Ask customers directly to decide where in the range you really are.
Takeaways for your next report
- AI assistant traffic is real, growing, and partly invisible in GA4.
- The floor: GA4's AI Assistant channel plus sources like utm_source=chatgpt.com.
- The ceiling: the floor plus unexplained growth in Direct visits to deep pages.
- Add 'ChatGPT or another AI assistant' to 'How did you hear about us?' to narrow the range.
- The pages AI sends people to are being quoted in answers — keep them accurate.
Chinmay Raibagkar
About author →Founder of DataLens AI. He helps non-technical teams read their ad and database numbers with confidence — which number to trust, what to do next, and what to ignore.