How to track Gemini traffic and leads in Google Tag Manager

Gemini is awkward to label in Tag Manager because it comes from the same company as your biggest traffic source. A click from the Gemini app comes from gemini.google.com, a click from Google search comes from www.google.com, and a click from an AI Overview or AI Mode also comes from www.google.com. A careless pattern labels the first as search, or all three as Gemini.

Step 1: Enable the built-in variables you need

1. In your web container, click Variables.
2. Under Built-In Variables, click Configure and make sure Referrer, Page URL and Page Path are ticked.

A click on a source link in Gemini on the web usually arrives with a referrer of https://gemini.google.com/. Old shared Bard chats can still come from bard.google.com.

Step 2: Build a RegEx Table, with Gemini above Google

1. Under User-Defined Variables, click New and choose RegEx Table. Set the input variable to {{Referrer}}.
2. Add the Gemini row first: pattern gemini\.google\.com|bard\.google\.com, output Gemini.
3. If you also want a label for ordinary Google search, add it below: pattern google\., output Google search.
4. Tick Set Default Value and enter none. In the advanced settings, untick Full Matches Only, since the referrer is a whole URL.

Order is the whole trick. Google's help page says RegEx Table lookups run from top to bottom, and the first match wins. gemini.google.com contains google., so if the Google row sits on top, every Gemini visit is labelled Google search and the Gemini row never fires. Name the variable AI source.

Step 3: Read the gemini UTM tag as a second signal

Since around 30 September 2026 some links in Gemini answers carry utm_source=gemini. Create a user-defined variable of type URL, set the component to Query and the query key to utm_source, and name it UTM source. On a tagged Gemini click it returns gemini. Treat either signal as Gemini.

The tag matters most for the Gemini mobile apps. App links often arrive with no referrer, so the UTM is the only clue left.

Step 4: Store the label before the visitor moves on

On the second page of the visit the referrer is your own site and the query string is usually gone, so both variables read empty. Add a Custom HTML tag with a page view trigger that fires only when the visit is Gemini (either condition from Step 3), and have it write the label and {{Page Path}} to two first-party cookies. Read them back with two 1st Party Cookie variables, and use those in every tag that fires on a form submission.

Don't clear the cookie on later pages. If you run a consent banner, give this cookie the same consent as your other analytics cookies.

Step 5: Send the label on, then test with a tagged URL

Add the cookie variables as parameters on your GA4 lead or form event and register them as custom dimensions in GA4's Admin or write them into hidden form fields. To test, click Preview and load your site with ?utm_source=gemini on the end of the address. In Tag Assistant, check that UTM source reads gemini and your Custom HTML tag fired, then open a second page and check the cookie variables. To test the referrer row, ask Gemini on the web about your business and click your site in its sources while Preview is running.

What Tag Manager can't see from Gemini

The AI Overviews and AI Mode rows can't be fixed in the browser: nothing tells them apart from a normal search click. Our post on tracking Google AI Mode traffic covers that side in Search Console. For the phone row, ask “How did you first hear about us?” on your form and on calls; our guide to wording that question explains why.

Other assistants to add to the same table

Add rows for chatgpt\.com, perplexity\.ai, claude\.ai and copilot\.microsoft\.com, all above any Google or Microsoft search row. ChatGPT also tags links with utm_source=chatgpt.com, covered in ChatGPT traffic in Google Tag Manager; Perplexity sends no tag, covered in Perplexity traffic in Google Tag Manager. Our free AI referral regex generator builds the full pattern, and the general Gemini tracking guide covers GA4.

Gemini leads in Tag Manager with Which AI Sent

Which AI Sent replaces Steps 1 to 5 with one tag. In your dashboard's Setup, click Connect Google Tag Manager and approve on Google's own screen. We add the tag in a new workspace and never publish, so you review it and click Submit; or paste it as a Custom HTML tag on All Pages. Gemini gets its own row, kept apart from Google search, and the script reads both the gemini.google.com referrer and the gemini tag. The source stays with the visitor for 90 days and is attached to their form, and the answer to “How did you first hear about us?” is recorded too, so each AI lead is marked Confirmed, Declared or Assisted. Details are on the Tag Manager integration page.