Google AI Mode cut clicks by nearly a fifth in the first controlled study

Author Profile

Sean Walsh

Director at Intelligency

Sean is a Director at Intelligency heading up our digital marketing and client services operations. Sean has 15+ years experiencing working both in-house and agency with brands including Lloyds, Alstom, Hitachi, Lufthansa, Viaplay, DFDS Seaways and Mercedes-Benz.

For the first time, we have controlled evidence of what Google’s AI Mode does to website traffic. When searchers were moved onto AI Mode, the share of searches that ended in a click to an external website fell by 18.8 percentage points. Users also trusted Google less and were more likely to try another search engine.

What happened

Researchers from the University of Pennsylvania and Northeastern University published the first randomised controlled experiment into how Google’s AI features change search behaviour. The paper, AI in Search Reduces Publisher Referrals Without Improving User Experience, was released in August 2026 and preregistered before the data was collected.

Most studies of AI search compare traffic before and after a change, which makes it hard to separate AI from seasonality, algorithm updates and everything else going on. This one did something different. A browser extension randomly placed US Google users into one of three groups for a week:

1. No AI: AI Overviews hidden and AI Mode redirected to normal results.
2. Current Google: search left exactly as it is today.
3. AI Mode: every search redirected to AI Mode.

Because the groups were assigned at random, differences in clicks can be attributed to the AI experience itself rather than to who the users were or what they searched for. That is why this study carries more weight than the many traffic analyses published over the past year.

What the study found

AI Mode reduced clicks to almost every type of destination. Removing AI from the results did the opposite, and users did not miss it.

The no-AI group clicked through 8.8 percentage points more often than people using Google as normal, with no measurable change in satisfaction. Put simply, the AI layer is taking clicks without making search feel better.

Users in the AI Mode group rated Google lower on trust, satisfaction, usefulness and relevance, and said they were more likely to switch to Bing. They also searched less often, by almost one session a day.

The test ran for one week, and the sample skewed younger and more educated than the UK search population. AI Mode was forced on people when, at the start of the study, it accounted for only 0.6% of searches. Google also changed its page code mid-study, so only around half of AI Overviews were successfully hidden in the no-AI group. That means the 8.8 point uplift is probably an underestimate.

Why it matters

This moves the AI search debate from opinion to evidence. Google has repeatedly said AI features send “higher quality” clicks and that people are searching more. This study shows that, when AI Mode becomes the default experience, fewer searches lead anywhere outside Google.

For most businesses, today’s impact is limited because AI Mode is still opt-in for most users. The risk lies in what happens if Google makes AI Mode more prominent, or the default. A site that relies on informational content to bring people in at the top of the funnel would see a meaningful drop in visits, even if its rankings stayed exactly the same.

There is a reporting consequence too. If traffic falls while rankings and impressions hold steady, it is easy to assume something has gone wrong with the SEO. In reality, the search results page is simply answering more of the question itself. Teams that track only sessions will misread what is happening.

Paid search is not immune either. The researchers recorded a large drop in ad clicks in the AI Mode group, but the study was run before Google began placing ads inside AI Mode, so that figure says more about where ads sit today than where they will sit next year.

What we recommend

There is no need to panic. These are the steps to take now so that a wider AI Mode rollout does not catch you off guard.

1. Separate visibility from visits in your reporting. Track impressions, rankings and AI citations alongside sessions. If impressions hold and clicks fall, that is a change in the results page, not a loss of position.
2. Find out which pages are exposed. Pages that answer simple, informational questions are the most likely to lose clicks to an AI summary. Pages built around a decision, a booking or a purchase are much harder for AI to replace.
3. Give people a reason to click. Original data, pricing, case studies, tools, expert opinion and clear next steps all offer something a summary cannot. Generic explainers are the content most at risk.
4. Earn the citation. Being named or linked in an AI answer is now a form of visibility in its own right. That means clear, well-structured pages, a credible author and mentions on trusted third-party sites.
5. Diversify where demand comes from. Email, social, referral partners and direct traffic all reduce reliance on a single results page that Google can redesign at any time.
6. Watch the conversion rate, not just the volume. If fewer but better-informed people arrive, enquiries per visit should rise. Measure leads and revenue, not sessions alone