How to track AI referral traffic from ChatGPT and Perplexity in GA4
AI assistants send visitors with referrers like chatgpt.com, perplexity.ai, gemini.google.com and copilot.microsoft.com. In GA4, create a custom channel group with an “AI assistants” channel that matches those sources, place it above Referral, and report on it monthly. Clicks from Google’s AI Overviews arrive as ordinary google / organic traffic, so track those with prompt checks instead.
- Most AI visits land in GA4’s Referral channel, mixed with every other site that links to you.
- A custom “AI assistants” channel pulls them into one line, and it works on historical data.
- Clicks from Google AI Overviews look like normal google / organic traffic and can’t be separated.
- Pair analytics with monthly prompt tracking to see mentions that never become clicks.
Where does AI traffic show up in GA4?
By default, most visits from AI assistants land in the Referral channel, mixed in with every other website that links to you. Some arrive with no referrer at all and fall into Direct, which happens when a link is opened from an app or copied from an answer.
That makes AI traffic easy to miss. A custom channel pulls it out into one line you can watch month by month, next to your organic search numbers.
Which AI referrers should you match?
These are the sources that matter for most stores today. Check your own Referral report for others:
| Assistant | Source in GA4 | Notes |
|---|---|---|
| ChatGPT | chatgpt.com | Links from ChatGPT often carry utm_source=chatgpt.com too |
| ChatGPT (older links) | chat.openai.com | Still appears on older shared conversations |
| Perplexity | perplexity.ai | Cites sources prominently, so it often sends clicks |
| Gemini | gemini.google.com | Separate from Google AI Overviews |
| Microsoft Copilot | copilot.microsoft.com | Some Copilot traffic may show as bing.com |
| Claude | claude.ai | Smaller volumes for most stores |
How do you set up an AI channel in GA4?
It takes about ten minutes and works on historical data too:
- In GA4, go to Admin → Data display → Channel groups and create a new channel group (copy the default one).
- Add a channel called AI assistants, with the condition “Source matches regex”.
- Use a pattern such as:
chatgpt\.com|chat\.openai\.com|perplexity\.ai|gemini\.google\.com|copilot\.microsoft\.com|claude\.ai - Move the new channel above Referral, otherwise GA4 files those visits under Referral first.
- Save, then switch your Traffic acquisition report to the new channel group.
- Add a monthly comparison to your reporting so the trend is visible, not just the total.
How do you see which pages AI sends people to?
The channel tells you how much AI traffic you get. The landing pages tell you why, and what to do more of:
- Go to Explore → Free form and start a new exploration.
- Add your new channel group as a dimension, plus Landing page and Session source.
- Add Sessions, Engaged sessions, Key events and, for stores, Purchase revenue as metrics.
- Filter to the AI assistants channel and sort by sessions.
- Look for patterns: buying guides, comparison pages and collection pages with answer-first copy usually lead.
Pages that already get AI visits are your best candidates for more answer-first content, FAQs and structured data.
How do you see whether AI visitors convert?
Traffic is only half the story. To see whether AI visitors buy or enquire, make sure your important actions are marked as key events in GA4: purchases, add-to-cart, form submissions, WhatsApp or phone clicks.
Then compare the AI assistants channel with Organic Search on key event rate and revenue per session. AI visitors often arrive with a narrower question already answered, so even small volumes can convert well. If they don’t, look at the landing page: does it carry on the answer the AI gave, or start from scratch?
What AI traffic can’t GA4 see?
Google AI Overviews. Clicks from AI Overviews and AI Mode come through as ordinary google / organic traffic, so analytics can’t separate them from normal search clicks.
Mentions without clicks. If ChatGPT recommends your store and the shopper searches your brand later, that visit looks like branded search or direct traffic. The recommendation never shows up as an AI referral.
That’s why we pair analytics with prompt tracking: a fixed set of shopper questions checked monthly across ChatGPT, Perplexity, Gemini, Copilot and AI Overviews. For our clients we report Generative AI performance alongside the AI referral channel.
What are the common setup mistakes?
If your AI channel shows nothing, check these first:
- The channel sits below Referral. GA4 assigns sessions to the first matching channel, so AI visits are filed as Referral.
- Matching the wrong field. Use Session source (the domain), not Medium.
- Forgetting to escape the dots. In a regex an unescaped dot matches any character; write
chatgpt\.com, notchatgpt.com. - Looking at the default channel group. Switch reports to your custom group, or the new channel won’t appear.
- Expecting AI Overviews in the channel. They arrive as google / organic and never will.
What goes in a monthly AI visibility report?
Keep it to one page. These five lines tell you whether AI search is working:
- AI referral sessions, this month vs last month and vs the same month last year.
- Key events and revenue from the AI assistants channel.
- Top AI landing pages, and what changed on them.
- Prompt visibility: how many of your tracked prompts mention you, by engine.
- Next actions: the two or three changes you’ll make before the next report.
Those are three of our clients’ generative AI performance figures after we started AEO and GEO work. The point isn’t the size of any one number. It’s that you can only manage what you measure month by month.