Track Gemini and AI Mode traffic in GA4
Measure Gemini visits with GA4's AI Assistant channel, understand why AI Mode counts as organic, and catch app traffic that lands in Direct.
GA4 now has a default AI Assistant channel. Google's help page says it covers visits "from sources like ChatGPT, Gemini, Deepseek, Copilot, or Grok", and that it "excludes Google's AI Overviews and AI Mode". Those two count as Organic Search, along with classic Google results. So Gemini app clicks on the web can be measured directly, but AI Mode and AI Overviews traffic can't be separated in GA4 alone. You need Search Console for those. A third complication is that clicks from the Gemini mobile apps often arrive without a referrer and land in Direct. This lesson sets up reporting that's honest about all three.
- AI Assistant channel rule: medium exactly matches "ai-assistant". GA4 sets medium "ai-assistant" and campaign "(ai-assistant)" when the referrer matches its list of AI assistants.
- AI Overviews and AI Mode = Organic Search in GA4. Use the Search Console Generative AI report for their impressions.
- Gemini app traffic may be under-counted. App clicks without a referrer usually appear as Direct.
- Never add UTMs to your own URLs for AI tracking. UTMs override referrer classification.
- Build one exploration: AI Assistant by source and landing page, plus key events.
Checked 5 November 2026 (CET) against Gemini Apps Help, the Gemini release notes, Google Workspace Help, Google Search Central, Search Console Help, the Gemini API docs and the Google blog posts cited in Sources. Google renames and moves Gemini features often, so confirm labels and limits in your own account. "Our view" marks MentionX opinion. Ledgerline is a fictional company used for illustration.
01Where does each Google AI surface show up in GA4?
| Surface | GA4 default channel | Typical session source | Separable in GA4? |
|---|---|---|---|
| Gemini app (web, desktop browser) | AI Assistant | The Gemini referrer, for example gemini.google.com | Yes |
| Gemini mobile apps (iOS, Android) | Often Direct (no referrer) | (direct) | Mostly no |
| AI Mode | Organic Search | No | |
| AI Overviews | Organic Search | No | |
| Gemini in Chrome or Workspace side panels | Varies with referrer | Varies | Partly |
| Gemini in Google Ads (Ask Advisor) | Not a traffic source | n/a | n/a |
The rule order matters: GA4 evaluates the default channel rules and the Organic Search rule (source in its search list, or medium "organic") catches google traffic first.
02How do you report on Gemini traffic?
Standard report
- Reports > Acquisition > Traffic acquisition.
- Primary dimension: Session default channel group. Find AI Assistant.
- Add secondary dimension: Session source. Gemini appears alongside ChatGPT, Perplexity and others.
- Add a filter on session source containing "gemini" for a Gemini-only view.
Exploration
- Explore > Free form.
- Dimensions: Session default channel group, Session source, Landing page + query string, Device category.
- Metrics: Sessions, Engaged sessions, Key events, Session key event rate.
- Filter: Session default channel group exactly matches AI Assistant.
- Rows: Session source, then Landing page. Columns: Device category.
The device split is useful. If Gemini traffic is almost all desktop while your audience is half mobile, app traffic is probably landing in Direct.
03Should you build a custom channel group?
The default AI Assistant channel is usually enough. Build a custom group if you need:
- AI assistants split by vendor (Gemini vs ChatGPT vs Perplexity).
- Sources added before Google's list does.
- Historical comparisons. Custom channel groups apply retroactively; the AI Assistant default may not cover older data the way you expect.
Example custom rule for a "Gemini" channel, placed above other channels:
Session source matches regex: (^|\.)gemini\.google(\.com)?$|^gemini$|bard\.googleTest the regex against your own Session source values first. See GA4 AI Assistant channel and regex for the full multi-vendor pattern.
04Why not tag links with UTMs?
You can't tag links Gemini creates, and tagging your own URLs breaks things:
| Mistake | Result |
|---|---|
| UTM parameters on canonical URLs | Duplicates, and every visitor shows the UTM source |
| utm_source only, with no medium | Medium (not set), so the visit lands in Unassigned |
| Internal links with UTMs | Session attribution overwritten |
In September 2026 some marketers reported Gemini links carrying a utm_source=gemini parameter. If you see it, GA4 reads it as a manual source. Check whether those sessions land in AI Assistant, Referral or Unassigned in your property before you change any rules.
05How do you connect GA4 with Search Console for AI Mode?
GA4 can't isolate AI Mode, so combine sources:
| Question | Source |
|---|---|
| How often do our pages appear in AI Overviews and AI Mode? | Search Console Generative AI performance report (impressions) |
| How much Google organic traffic do key pages get? | GA4 Organic Search by landing page, or Search Console Performance |
| How much Gemini app traffic, and does it convert? | GA4 AI Assistant, source Gemini |
| Is mobile app traffic hiding in Direct? | GA4 Direct deep-landing-page check |
Link Search Console and GA4 (guide), and see lesson 19 for the Generative AI report.
Our view: report three numbers to leadership. These are AI Assistant sessions and key events (measured), Generative AI impressions from Search Console (measured), and estimated app traffic (modelled, labelled). Don't add them together.
06Worked example: Ledgerline
Ledgerline is a fictional accounts-payable software company. Details are illustrative.
| Metric (October 2026) | Value (illustrative) | Source |
|---|---|---|
| AI Assistant sessions, all sources | 1,940 | GA4 |
| of which Gemini | 410 | GA4, session source |
| Gemini sessions, desktop share | 92% | GA4 device |
| Gemini key events (demo requests) | 18 | GA4 |
| Direct sessions to /integrations/netsuite | Up 140% month on month | GA4 |
| Generative AI impressions | 31,000 | Search Console |
Walkthrough
- The analyst built the AI Assistant exploration and the Gemini source filter.
- The 92% desktop share suggested mobile app traffic was going to Direct.
- Direct growth on the NetSuite page matched a new Gemini citation found in prompt tracking.
- The monthly report listed measured Gemini sessions (410), estimated app traffic (a range) and Search Console impressions as separate rows.
- Demo requests from Gemini converted at a higher rate than average (illustrative), so the team prioritised pages Gemini cites.
07Common mistakes
- Expecting AI Mode in the AI Assistant channel.
- Adding UTMs to site URLs.
- Summing measured and estimated traffic.
- Ignoring device splits.
- Not checking older data, where AI sources may sit in Referral.
08Try it yourself
Open Traffic acquisition, find AI Assistant, and add Session source. Note the Gemini sessions and device split for the last 28 days. Then check Direct sessions to your three most-cited pages over the same period.
09Quick quiz
1. Which channel does AI Mode traffic fall into?
Answer: Organic Search.
2. What medium does GA4 set for AI assistant referrals?
Answer: "ai-assistant", with campaign "(ai-assistant)".
3. Why might Gemini traffic be under-counted?
Answer: Mobile app clicks often have no referrer and land in Direct.
10What should you check before the next lesson?
- The AI Assistant exploration is saved.
- The Direct anomaly check is set up.
- Search Console is linked to GA4.
Previous: Merchant Center, UCP and shopping visibility in Gemini. Next: Search Console AI reports for AI Mode and AI Overviews. Or return to the Gemini for Marketers track. Related: Track AI traffic in GA4, Track AI referral traffic with GTM, Track Perplexity traffic in GA4.
11Common questions
Which GA4 channel does Gemini traffic go to? Web visits referred by Gemini go to the AI Assistant default channel, where GA4 sets medium to ai-assistant and campaign to (ai-assistant). Untagged app visits with no referrer usually appear as Direct.
Is AI Mode traffic in the AI Assistant channel? No. GA4's AI Assistant channel excludes Google's AI Overviews and AI Mode. That traffic is part of Organic Search from google.
Should I add UTM tags to my URLs for Gemini? No. Never add UTMs to canonical or internal URLs. UTMs override referrer classification and can push visits into the wrong channel.
Questions people ask
3 answersWhich GA4 channel does Gemini traffic go to?
+
Web visits referred by Gemini go to the AI Assistant default channel, where GA4 sets medium to ai-assistant and campaign to (ai-assistant). Untagged app visits with no referrer usually appear as Direct.
Is AI Mode traffic in the AI Assistant channel?
+
No. GA4's AI Assistant channel excludes Google's AI Overviews and AI Mode. That traffic is part of Organic Search from google.
Should I add UTM tags to my URLs for Gemini?
+
No. Never add UTMs to canonical or internal URLs. UTMs override referrer classification and can push visits into the wrong channel.
Sources
- Analytics Help, Default channel groupsupport.google.com
- Google Search Central, AI features and your websitedevelopers.google.com
- Search Console Help, Generative AI performance report (Search)support.google.com
- Analytics Help, Create a channel groupsupport.google.com
- All accessed 5 Nov 2026.