Google’s Gemini has quietly stopped adding tracking tags to the links it cites in its answers, removing a small marker that had helped publishers measure traffic coming from the chatbot. The tags, which labelled outgoing links with utm_source=gemini, appeared in early September and then vanished around September 28, according to analysts who tracked the change. No announcement of the removal has surfaced, and the desktop version of Gemini still passes referrer data, so visits can still be recognised, though less precisely than before.
What changed, and when
UTM parameters are short tags added to a web address so analytics tools can record where a visit came from. When Gemini began attaching utm_source=gemini in early September, publishers could separate Gemini clicks from other traffic in Google Analytics. That separation lasted only about three weeks before the tags disappeared.
The disappearance was charted by analyst Natzir, who shared a graph showing Gemini’s UTM tags growing for three weeks and then vanishing overnight. Another observer, Xyborg, reported the same drop around September 28 in Gemini’s answers, giving the timeline a second witness.
Google’s John Mueller commented on Reddit that he had seen the UTM parameters on Gemini links a month or so earlier. His remark fits the September window, but it does not explain why the tags went away, and no Google statement on the removal has surfaced.
A familiar pattern for AI traffic
The episode echoes a recent ChatGPT case, in which a sharp drop in referral traffic turned out to be a bug rather than a deliberate change. ChatGPT’s missing UTM tags were confirmed by OpenAI and fixed within days, with tagged clicks recovering to near their earlier levels.
Nothing so far suggests the same explanation for Gemini. No fix or statement has followed the September disappearance, which leaves the change looking deliberate, even if unannounced, and publishers should treat the tag as gone rather than temporarily broken for now.
One detail makes the Gemini case different from a clean break. On the desktop web version, Gemini still passes referrer data, and visits carrying a gemini.google.com referrer stayed flat through the change. The tracking loss is therefore partial: publishers lose the precise UTM label, but not every signal.
Why It Matters
For publishers and search marketers, the missing tag complicates an already murky picture of AI referral traffic. Without utm_source=gemini, Gemini visits blend more easily into broader traffic buckets, and teams that built reports around the tag will see a break in their series from late September onward.
That measurement gap matters because AI answers are becoming a real, if still modest, source of clicks. A small study of AI Overview clicks published this week found a click-through rate of about 0.9 percent, a reminder that AI visibility is worth measuring even when the numbers look small.
The gap is widest on mobile. From the iOS app, Gemini opens links in its own web view and sends no referrer, so those visits land in Direct traffic in Google Analytics. Only the Gemini iOS user agent in server logs offers a trace, and few teams check logs routinely.
What publishers should do now
Publishers should first check whether their Gemini traffic series breaks in late September, and note the break in their reports so later comparisons are not misread. Where the tag once fed a dedicated dashboard, the referrer field on desktop web traffic can serve as a rough replacement, though it will undercount mobile visits.
Server logs deserve a second look for teams that need a fuller count, since the iOS user agent survives there even when analytics shows Direct. Above all, publishers should avoid treating the UTM disappearance as proof that Gemini traffic fell: the visits may still be arriving, only under a different label.
Background
Gemini’s citations have become a closely watched signal for publishers tracking AI search, and the September UTM experiment briefly promised cleaner measurement before quietly ending.
Source: Search Engine Roundtable report
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