A Reddit user spotted Gemini appending UTM parameters to the links it sends to websites, and John Mueller confirmed he sees them too. Google hasn't documented it — but it's the first reliable signal of how much traffic Gemini actually sends.
2026-10-03 · by Moe Ameen
Google's Gemini has quietly begun adding UTM parameters to the links it surfaces to websites — a tracking tag appended to the URL that lets analytics tools attribute a visit to Gemini rather than lumping it into "direct" traffic. The change surfaced in late September 2026 when a user on Reddit noticed the tags on Gemini's outbound links and asked whether anyone else was seeing them. Google's John Mueller replied publicly that he sees them too, which is as close to confirmation as the change has gotten.
It is not officially documented. Google has not announced the behavior, published the exact parameter format, or said under what conditions Gemini adds the tag — the working assumption is that it fires when Gemini cites or links a source in an answer, but that is inference, not a documented rule. The parameter identifies Gemini as the traffic source in the style of a standard campaign tag; what it is NOT yet is a published, reliable contract you can build reporting on top of. Treat it as an early signal, not a finished feature.
The reason this matters more than it looks is that referrer data from AI assistants is unreliable. Referrers pass through inconsistently from Gemini — a large share of clicks, especially from mobile apps and from Android's assistant invocations, arrive with the referrer stripped entirely, so they land in analytics as anonymous "direct" visits. A UTM tag rides in the URL itself and survives where a referrer doesn't, which is why a tagged link is a sturdier attribution signal than hoping the browser passes a referrer along. This also lines Gemini up with ChatGPT, which already appends a documented `utm_source=chatgpt.com` to links grounded in live web sources; Perplexity and Claude have not consistently tagged their outbound links, so Gemini's move narrows a measurement gap that has frustrated anyone trying to size AI-driven traffic.
A UTM tag is a ruler, not a growth tactic — it tells you Gemini is sending real clicks, but the way you get more of them is to be the source Gemini keeps citing. That is a volume-and-consistency problem: assistants surface brands that publish clear, on-brand, frequently-updated content across the surfaces they read, and describe themselves the same way everywhere. Producing at that cadence by hand is where most creators stall, and it is exactly what [Kompozy](/) is built to carry. Point it at one source — a video, a transcript, a set of notes — and it generates the citeable assets an assistant can actually ground an answer in: [blog articles and email newsletters](/glossary/output-buckets), platform-native text, [persona and avatar shorts](/glossary/persona-shorts), brand-exact carousels, and quote cards, all governed by a [Persona Brief](/glossary/persona-brief) so your name, claims, and voice stay identical across every one.
So the practical loop the UTM tag unlocks is measure, then feed. Use the tag (and GA4's native AI Assistants channel) to confirm Gemini is a real referral source, then use Kompozy's [autopilot](/glossary/autopilot) to keep shipping on-brand content across the eight social platforms plus blog and email on a deliberate schedule, so there is always fresh, consistent material for Gemini to cite. For the full attribution setup — why referrers lie, how the AI Assistants channel works, and what to actually track — see our guide on [tracking Gemini and AI-assistant traffic](/guides/tracking-gemini-ai-assistant-traffic).
They are campaign tracking parameters that Google's Gemini has quietly begun appending to the links it surfaces to websites. The tag identifies Gemini as the traffic source in the URL itself, so analytics tools can attribute the visit to Gemini instead of filing it under anonymous 'direct' traffic. Google hasn't documented the exact format or the conditions that trigger it, so it's best treated as an early, unofficial signal rather than a finished, reliable feature.
The behavior was spotted by a Reddit user in late September 2026 and reported in early October 2026, when Google's John Mueller acknowledged publicly that he sees the tags too. Google has not announced a launch date or documented the change, so the exact rollout timing is unknown — the discovery is community-sourced, not an official Google announcement.
Because referrer data from AI assistants is unreliable — a large share of Gemini clicks, especially from mobile apps and Android assistant invocations, arrive with the referrer stripped and get counted as 'direct' visits. A UTM parameter travels inside the URL and survives where a referrer doesn't, so a tagged link is a far sturdier attribution signal. It lets you separate real Gemini referrals from the 'direct' bucket in GA4 and gauge how much traffic Gemini actually sends.
No. Gemini links to your real canonical URL, so adding utm_source=gemini yourself would stamp that tag onto visitors arriving from organic search, email, and social — mislabeling them all as Gemini traffic and corrupting the very number you're trying to measure. Let Gemini add its own tag; your job is to read it in analytics, not to apply it manually.