Open Reports, then Acquisition, then Traffic acquisition, and look for the AI Assistant channel. Google Analytics 4’s default channel group includes an AI Assistant channel for visitors who arrive from sources like ChatGPT, Gemini, DeepSeek, Copilot and Grok. It won’t catch every AI visit, and it can’t show when an assistant mentions you without a click, but it’s the quickest reliable starting point.
Until recently, tracking AI traffic meant building your own channel with regular expressions. GA4 now does much of it for you. This post covers where to find it, how to build a more useful report, and the gaps to be aware of.
Where AI traffic shows in GA4
GA4 places visits from recognised AI assistants in a default channel called AI Assistant, which appears in the Traffic acquisition report. Google says the medium is set to “ai-assistant” when the referrer matches its list of AI assistants, so these visits no longer get mixed in with general referral traffic.
Google’s help page on the default channel group describes AI Assistant as the channel by which users arrive from sources like ChatGPT, Gemini, DeepSeek, Copilot or Grok. When the referrer matches Google’s list, the medium is set to “ai-assistant” and the campaign to “(ai-assistant)”.
To see it:
- In GA4, go to Reports, then Acquisition, then Traffic acquisition.
- Make sure the table’s primary dimension is Session default channel group.
- Find the AI Assistant row. If it isn’t there, your property hasn’t recorded any matching sessions in the date range.
- Change the primary dimension to Session source / medium, or add it as a secondary dimension, to see which assistants the visits came from.
ChatGPT also helps here. OpenAI’s publishers and developers FAQ says ChatGPT automatically adds utm_source=chatgpt.com to referral links from its search results, so those visits carry chatgpt.com as their source even when the referrer is lost.
Build a report that shows what AI visitors do
A channel total on its own tells you little. The useful report shows which assistants send visitors, which pages they land on, and whether they convert. You can build that in a few minutes with an Exploration, filtered to the AI Assistant channel.
- Go to Explore and start a Free form exploration.
- Add the dimensions Session default channel group, Session source / medium and Landing page + query string.
- Add the metrics Sessions, Engaged sessions, Key events and, for shops, Total revenue.
- Add a filter: Session default channel group exactly matches AI Assistant.
- Set rows to Session source / medium, then Landing page + query string.
- Set the date range to at least three months, since AI referral numbers are usually small.
| What to look for | Why it matters |
|---|---|
| Which assistants send visits | Shows where your business is actually being linked |
| Landing pages | Shows which content assistants link to, often guides and FAQs rather than the homepage |
| Engagement rate against other channels | AI visitors have often already read a summary, so they can arrive better informed |
| Key events and revenue | Shows whether AI visits turn into enquiries or sales |
What GA4 can’t show
GA4 only records visits where someone clicks through and the referrer is passed on. It can’t show when an AI assistant names your business without a click, and some AI visits arrive without referrer information, so they’re counted as direct traffic instead. Treat the AI Assistant channel as a minimum, not a total.
There are three main gaps:
- Mentions without clicks. An assistant can recommend your business by name, and the person may search for you later or ring you directly. GA4 sees that as a branded search or no visit at all.
- Missing referrers. Visits from some apps, or where the referrer is stripped, show as direct.
- Assistants not on Google’s list. Any AI source not recognised by GA4 falls into Referral instead. Check the Referral channel for AI tools such as perplexity.ai or claude.ai, which weren’t named in Google’s list when this was written.
Two other sources fill some of the gaps. Search Console includes AI Overviews and AI Mode within its Performance report, according to Google’s AI features documentation, although they aren’t separated out. And regular checks of the questions your customers ask, across the assistants that matter, show whether you’re named even when nobody clicks.
Catch AI tools GA4 doesn’t classify
If AI tools you care about appear under Referral rather than AI Assistant, create a custom channel group that adds them. Copy the default group, add a channel with a source condition matching those domains, and place it above Referral so it takes priority.
- Go to Admin, then Data display, then Channel groups.
- Copy the default channel group so the original stays intact.
- Add a new channel, for example “AI tools (other)”.
- Set the condition to Source matches regex, listing the domains you’ve found in your referral report, for example
perplexity|claude\.ai. - Drag the new channel above Referral and save.
Custom channel groups can be applied to historical data in reports, so you don’t lose earlier visits. Only add domains you’ve actually seen in your data, and review the list every few months as tools change.
What bots in your server logs mean
Server logs may show AI bots such as ChatGPT-User or OAI-SearchBot visiting your pages, but those are automated fetches, not people. GA4 doesn’t record them. They tell you an assistant read your page, which is useful context alongside the visits GA4 does record.
OpenAI’s crawler documentation explains that OAI-SearchBot is used for search, GPTBot for training, and ChatGPT-User for certain user actions, such as visiting a page when someone asks ChatGPT a question. Seeing ChatGPT-User in your logs means someone’s question led ChatGPT to fetch your page, even if they never clicked through.
If you’re seeing no AI traffic at all, check robots.txt isn’t blocking OAI-SearchBot. OpenAI’s documentation says sites that opt out of OAI-SearchBot won’t be shown in ChatGPT search answers.
What I learned
AI referral numbers on most small business sites are still small next to Google, and it’s easy to dismiss them. I look at them anyway, because the landing pages are telling. Assistants tend to link to the most specific, useful pages on a site, which shows what content is earning trust.
The bigger lesson is not to treat GA4 as the whole picture. When a business tells me people have started mentioning ChatGPT on sales calls, that rarely shows up as AI Assistant sessions. It shows up as more branded searches and direct enquiries. That’s why I pair GA4 with Search Console and regular visibility checks.
The AI visibility tracking service combines all three, so you can see both the clicks and the mentions.
FAQ
Does GA4 track ChatGPT traffic automatically?
Yes, for visits where the referrer is passed. GA4’s default channel group includes an AI Assistant channel for visitors arriving from sources like ChatGPT, Gemini, DeepSeek, Copilot and Grok. Find it in the Traffic acquisition report. Visits without referrer information are counted as direct, so the channel shows a minimum figure.
Why is ChatGPT showing as referral traffic in GA4?
It may be because the visits were recorded before GA4 recognised the source, or because the referrer doesn’t match Google’s list of AI assistants. Check the Session source / medium dimension. If an AI tool you care about sits under Referral, a custom channel group can reclassify it.
Can I see when ChatGPT mentions my business without a click?
Not in GA4. Analytics only records visits to your site. To know whether ChatGPT or other assistants name your business, you need to check the questions customers ask regularly and record the answers. A rise in branded searches in Search Console can also hint at mentions.
Is AI assistant traffic worth tracking for a small business?
Yes, even while the numbers are small. It shows which pages assistants trust enough to link to, whether those visitors convert, and how the channel is changing over time. Tracking it now also gives you a baseline to compare against as AI search use grows.
More on AI search:
- Is AI search taking your clicks?
- How ChatGPT decides which businesses to recommend
- The AI search guide
If you’d like help setting this up, get in touch or ask for a free assessment.
Sources
- Default channel group, Analytics Help, accessed 15 September 2026. Supports: the AI Assistant channel, the sources it names, and the “ai-assistant” medium and campaign.
- AI features and your website, Google Search Central, accessed 15 September 2026. Supports: AI Overviews and AI Mode included in Search Console’s Performance report.
- Overview of OpenAI crawlers, OpenAI, accessed 15 September 2026. Supports: OAI-SearchBot, GPTBot and ChatGPT-User roles, and the effect of opting out of OAI-SearchBot.
- Publishers and developers FAQ, OpenAI Help Center, accessed 15 September 2026. Supports: ChatGPT adding utm_source=chatgpt.com to referral URLs.