Definition
The Great Decoupling is the name for a pattern in Google Search Console where impressions keep rising while clicks flatten or fall, so two lines that used to move together separate into what SEOs call a 'crocodile mouth' chart. It is most often blamed on AI Overviews, which show a site's link while answering the question on the results page.
The term was coined by Darwin Santos on X on May 31, 2025 and spread after Barry Schwartz covered it on Search Engine Roundtable on June 3. In June 2025 Ahrefs published its own numbers (Ahrefs): daily impressions and clicks on the Ahrefs blog had a positive correlation of 0.425 in the second half of 2024 and a negative correlation of minus 0.352 in the first half of 2025. Ahrefs also found that AI Overview presence in its data rose 116% around the March 2025 core update, the same period the gap widened.
Three forces sit behind the pattern:
- Fewer clicks per impression. Ahrefs measured in April 2025 that an AI Overview correlated with a 34.5% lower click-through rate for the top result, and in a February 2026 update using December 2025 data put the figure at 58%. This is zero-click search at scale.
- More impressions. AI Overviews can cite several URLs for one query, and each cited link can register an impression. Google's John Mueller clarified that a URL shown both in an AI Overview and in the blue links still counts as one impression.
- Inflated baselines. When Google disabled the &num=100 results parameter around September 10, 2025, a LOCOMOTIVE analysis of 319 properties found that 87.7% lost impressions, which suggested rank trackers loading 100-result pages had been inflating desktop impressions. Brodie Clark and others asked whether part of the decoupling had been a measurement artifact.
So the honest reading is that the click decline is real and well documented, while some of the impression growth was not. Any year-over-year comparison that crosses September 2025 needs a note about the reset.
In 2026 site owners can finally separate the AI share of impressions. Google's generative AI performance report, available to all sites since August 31, 2026, shows impressions from AI Overviews and AI Mode by page, while the main Performance report still holds the clicks. Pages with high AI impressions and a falling click-through rate are where the decoupling hits hardest.
For reporting, the practical consequence is that impressions stop being a proxy for traffic, and traffic stops being a full proxy for influence. Teams that adapt usually report three things side by side: clicks and conversions from search, AI Overview impressions or citations per page, and brand visibility inside AI answers across tracked prompts, often expressed as AI share of voice. Our post on AI search visibility KPIs covers how to set those targets.
Examples of The Great Decoupling
- A B2B software blog sees impressions up 40% year over year while clicks fall 25%. Filtering Search Console to its 'what is' explainer posts shows the gap is concentrated on queries that now trigger an AI Overview.
- An agency notices a sudden drop in desktop impressions and a jump in average position for every client in mid-September 2025, traces it to the removal of &num=100, and resets its reporting baseline to that week.
- A recipe publisher uses the generative AI performance report in September 2026 and finds that most of its new impressions since 2025 come from AI features, which explains why sessions have not followed.
- A marketing director replaces 'organic impressions' as a headline KPI with a scorecard of organic conversions, AI citations per page and share of voice across 200 tracked prompts.
