How to see ChatGPT, Perplexity and Gemini traffic in your analytics (and why GA4 hides most of it)
Update (June 14, 2026): On May 13, 2026 GA4 shipped a native AI Assistant channel, so the custom-channel-group step below is no longer required for ChatGPT, Gemini and Claude — they now roll up automatically. But Perplexity still lands in Referral, Google's own AI Overviews and AI Mode count as Organic Search, and stripped-referrer clicks still fall into Direct, so the manual group below remains the way to catch what the native channel misses. See the follow-up: GA4 finally has a native "AI Assistant" channel — here's what it still hides.
If you want to see how many visitors arrived from ChatGPT, Perplexity, Gemini or Claude, the short answer is: look at your referrers and group the AI-assistant domains together. In Google Analytics 4 that means building a custom channel group with a regex (or, since May 2026, leaning on the native AI Assistant channel for the sources it recognizes — see the update note above). In some tools it happens on its own.
The longer answer is more honest. AI assistants have become a genuine referral channel — Contentsquare measured AI-referred traffic growing roughly 600% from 2024 to 2025, though it is still a small slice of most sites' total. But a large share of those sessions arrive with no referrer at all: a link copied out of a chat, or a mobile-app webview that strips the referer header. Traffic with no referrer is invisible to every analytics tool — GA4, Simplytics, all of them. Nobody can recover a referrer that was never sent. So this post is about the part you can see, and how to stop GA4 from hiding it.
Why GA4 buries AI traffic in "Direct"
GA4 does recognize some AI sources in its default channel grouping. The catch: it only attributes a session to an AI source when that session arrives with an intact referrer. When ChatGPT's mobile app or a copied link sends a visitor with no referer header, GA4 has nothing to match — so the session lands in Direct, alongside bookmarks and typed-in URLs.
How big is that dark slice? Third-party analyses put it in a wide range — roughly 20–70% of AI-referred sessions arrive with no usable referrer, depending on the platform and how people share links. (martech.org and authoritytech.io both report figures in that band.) Behavior differs by platform: Perplexity usually passes perplexity.ai as the referrer, while ChatGPT traffic often arrives via chatgpt.com but a meaningful chunk — app and copy-paste — carries no referrer at all.
So before you do anything, set expectations: you are recovering the referred AI traffic, not the stripped portion. The stripped portion stays in Direct, everywhere.
The GA4 fix: build a custom channel group
GA4's defaults will not reliably bucket AI sources for you, so you build a custom channel group that matches AI referrer/source domains with a regex. In Admin → Data display → Channel groups, create a new group and add a channel — call it "AI assistants" — defined by a condition like Source matches regex:
chatgpt\.com|chat\.openai\.com|openai\.com|perplexity\.ai|claude\.ai|gemini\.google\.com|copilot\.microsoft\.com|you\.com|poe\.com|phind\.com|deepseek\.com|grok\.com|meta\.ai|mistral\.ai
A few things to know going in:
- You maintain the list. The regex above is an abbreviated starter set — Simplytics matches more hosts than this — and new assistants launch constantly, so it is only as current as the last time you edited it.
- Order matters.
gemini.google.comhas to be matched as AI before GA4's Organic Search rules claim it as agoogle.*source, so place your AI channel above Search. - The default reports do not change retroactively. You can apply the custom group as a dimension to break down historical sessions, but it only replaces your primary channel grouping going forward — past data keeps its original default bucketing.
None of this is exotic — it is just homework. And it is on top of GA4's other setup tax: the consent banner the EU requires, plus the ~140 KB of JavaScript gtag.js makes every visitor download.
The shortcut: have the tool do it
The measurable part of this problem — grouping known AI hostnames into one channel — does not actually need regex homework. It is a fixed list of domains that a tool can ship with.
Simplytics does exactly that. It is a cookie-less, ~1.9 KB analytics tool that classifies every referrer into a channel automatically, and one of those channels is AI. Out of the box, with no configuration, these hostnames roll up into the AI channel:
chatgpt.com, chat.openai.com, openai.com, perplexity.ai, claude.ai, gemini.google.com, bard.google.com, copilot.microsoft.com, you.com, poe.com, phind.com, deepseek.com, chat.deepseek.com, grok.com, meta.ai, mistral.ai, chat.mistral.ai, kimi.com, qwen.ai
The other channels — Direct, Search, Social, Email, Referral — are detected the same way. You can see the Channels table on the live demo.
The two approaches side by side
| GA4 | Simplytics | |
|---|---|---|
| AI sessions with referrer | ChatGPT/Gemini/Claude auto since May 2026; Perplexity and others still need a custom channel group | Grouped into an AI channel automatically |
| AI sessions with stripped referrer | Counted as Direct | Counted as Direct |
| Setup to see AI traffic | Custom channel group + maintained regex | None |
| Cookie banner needed | Usually (EU) | No (cookie-less) |
| Script weight | ~140 KB gtag.js | ~1.9 KB |
| Price | Free | $1/month |
The honest caveat
Be clear about what this does and does not buy you. Simplytics groups referred AI traffic into a channel with zero setup — but it cannot see stripped-referrer AI sessions either. In the same code that builds the AI channel, a visit with no referrer is classified as Direct, exactly like GA4. We do not estimate or statistically reconstruct that dark traffic. Some tools market a paid "traffic recovery" feature that tries to model the referrer-less portion; Simplytics does not, and we would rather say so than imply a number we did not measure.
Simplytics also does not do everything GA4 does. There is no ads attribution, no audiences, no BigQuery export. If you need those, you need a bigger tool. What you get instead is the essential picture — visitors, views, referrers grouped into channels including AI, countries, devices, sessions, custom events, outbound clicks, UTM campaigns, funnels — from a ~1.9 KB script for $1/month, versus the $9–15/month of Plausible and Fathom or the configuration overhead of "free" GA4.
If that trade sounds right, the Google Analytics comparison and the other comparisons lay out the rest honestly. The one-line version: Simplytics is a cookie-less analytics tool that shows your ChatGPT, Perplexity, Gemini and Claude referral traffic in a dedicated AI channel, automatically, for $1/month — with the same honest limit every tool has on referrer-less traffic.
AI-traffic ranges cited link to their sources; per-platform referrer behavior changes quickly, so the regex above is a starting point, not a permanent list.