Google tests tracking parameter on AI Overview and AI Mode links
Marketer Tom Pool spotted a ?st_source=ai_overview parameter appended to links inside Google’s AI Overviews and AI Mode, posting screenshots to LinkedIn, per Search Engine Roundtable. The tag would let site owners separate clicks that come from AI Overviews and AI Mode from ordinary search-result clicks — something currently invisible in most analytics tools. Google has not confirmed the test, and Search Engine Roundtable’s own attempt to reproduce it across several browsers did not surface the parameter; it comes a day after Google’s John Mueller confirmed Gemini is quietly adding UTM parameters to its own outgoing links.
Why it matters: A working click tag on AI Overview links would close an attribution gap that currently leaves publishers unable to separate that traffic from ordinary search clicks.
The record: GoogleGoogle AI OverviewsGoogle AI Mode
Glossary: AI OverviewsAI Mode
Via Search Engine Roundtable ↗
Posted to the wire October 2, 2026. Edited by Joe Balewski.