AI Overviews Auto-Expand Into AI Mode, Raising Stakes for SEO

The overview is now the page

Google's AI changes this year add up to a different search results page. On August 27–28, Google confirmed that some AI Overviews now expand on their own into longer answers in the style of AI Mode. The manual "Show more" button is gone for those queries, and the "Ask anything" follow-up box loads by default.59 A Google spokesperson said the overviews may "dynamically expand for topics where our systems determine it's most useful for people."9 For businesses, the practical effect is that the traditional ten blue links sit much further down the screen.9

This did not come out of nowhere. In January, Google made Gemini 3 the default model for AI Overviews worldwide and let mobile users carry an overview into an AI Mode conversation without losing context.8 At I/O on May 20, the company merged the two surfaces into one flow running on Gemini 3.5 Flash. It said AI Mode had passed 1 billion monthly users and AI Overviews 2.5 billion.2 One tracker called the merger the moment AI Overviews stopped being an add-on and became the main entry point to Google's AI search.1

The commercial and local layers are also moving inside the AI answer. In mid-September, Google was seen testing sponsored text links inside AI Mode answers and began labeling some local knowledge panels as AI Overviews. Those panels describe a business using its wider web presence, not just its Business Profile.2 On September 22, Google began auto-enrolling eligible US Shopify merchants in native checkout inside AI Mode and the Gemini app.8

How much traffic is at stake

The central question for any business is whether AI answers reduce clicks. The evidence points clearly one way, even though the exact size of the effect varies by study.

The largest-scale figure comes from Ahrefs. Using December 2025 data, it found that an AI Overview is associated with a 58% lower click-through rate for the top-ranking page, up from the 34.5% drop it reported in April 2025.21 The effect reaches down the page, with estimated drops of about 51% at position two and 46% at position three.24

Controlled experiments give a smaller but more reliable number. In a randomized field study of 1,065 desktop Chrome users, Saharsh Agarwal and Ananya Sen found that showing an AI Overview cut outbound organic clicks by 39.8% and increased zero-click searches by 34.5%. Clicks on sponsored results did not change.25 When the overview was hidden, outbound clicks per search rose from 0.37 to 0.62.25 Most of the effect came from overviews in the top slot, which is where more than 87% of them appear.25

A separate preregistered experiment by researchers at the University of Pennsylvania and Northeastern looked at AI Mode. It found that AI Mode cut external click-through by 18.8 percentage points and made users more likely to switch to rival search engines.22 Pew Research, using browsing data, found that people clicked a traditional result on 8% of visits when an AI summary appeared, compared with 15% when none did. Links inside the summary got clicks on just 1% of visits.24

Where the numbers disagree

Not every figure deserves equal weight, and there is a real dispute over attribution. A review of the Ahrefs data in Clownfish TV's D/REZZED newsletter found that position-one click-through also fell sharply on informational keywords that never showed an AI Overview, from 7.6% to 3.9%. That suggests part of the headline 58% reflects a wider decline in clicks.26 The Reuters Institute, drawing on Chartbeat data, reported that Google search referrals to publishers fell 33% globally between November 2024 and November 2025. It also cautioned that algorithm changes and changing audience habits played a role alongside AI Overviews.2428

Google's usage figures are also contested. Google cites 1 billion monthly AI Mode users, but SparkToro's analysis of Similarweb clickstream data from January to April 2026 found that AI Mode accounted for only 0.34% of US searches. The same study found that 68% of searches ended without a click.2 Estimates of how often AI Overviews appear also vary. Google put it at roughly half of US queries in February 2026, while third-party trackers estimate 43–48%.6

The most defensible reading is this. The randomized studies show that AI answers cause click losses on the queries where they appear. The largest aggregate traffic-loss figures mix that effect with other pressures. Either way, businesses face a structural problem, not a temporary one.

The brand exception is shrinking

Branded searches have been a bright spot. Amsive found that AI Overviews lowered average click-through rates by 15.49% overall but raised them by 18.68% on branded queries, partly because only 4.79% of branded keywords triggered an overview.1 That protection may be fading. DemandSphere reported that AI Overviews appeared on 26% of its tracked branded keywords on September 1 and 90% on September 27, even though Google announced no change.1

Being cited inside the answer carries a measurable advantage. Brands cited inside AI Overviews earned 35% more organic clicks and 91% more paid clicks than brands that were left out.27 Google says people are twice as likely to click through to a source a user has marked as preferred. More than 345,000 sources had been selected when it reported that figure.1

Core updates add to the turbulence

Ranking volatility makes all of this harder to manage. SE Ranking found that after the March 2026 spam and core updates, 79.5% of top-three URLs changed position and 24.1% of top-ten pages dropped out of the top 100 entirely.33 The winners were strong brands, official sources and sites with their own data, while aggregators and intermediaries lost ground.31 Analysts including Glenn Gabe described the May 21–June 2 core update as heavier still.37 Google had not confirmed a new core update in September.5

The important change for answer visibility is that ranking in the top ten no longer guarantees a citation. Industry data compiled by Omnibound shows the overlap between AI Overview citations and the organic top ten falling from 76% in mid-2024 to between 17% and 38% by February 2026.15 Another analysis found that AI Overview sources change often. In 53% of prompts tracked over 17 weeks, no source changed at all. In 19%, cited domains turned over at about 46% a week.1

What answer engine optimization actually means

The consulting industry has adopted the terms answer engine optimization (AEO) and generative engine optimization (GEO). Definitions vary. Some firms treat them as separate disciplines, one focused on getting content extracted as a direct answer and the other on getting cited in AI-written summaries.11 Directive Consulting argues that in practice they are the same playbook.16 Our view is that Directive is closer to the truth, and that businesses should be wary of anyone selling AEO as a separate product.

Google's own guidance supports that caution. Its documentation still says there are no extra requirements and no special schema needed to appear in AI Overviews or AI Mode.2 One AEO explainer warns against treating the practice as a shortcut around weak SEO.19 The academic evidence behind GEO is more modest than the marketing suggests. A 2024 study by Aggarwal and colleagues found that adding quotations from credible sources increased a source's share of an AI answer by about 41%, and adding statistics by about 31%. Keyword stuffing made no meaningful difference.11

The sensible approach puts the work in order. Strong organic search performance gets a page into the set of pages the AI reads. Clear, quotable answers make the content easy to extract. Original evidence and outside authority make it more likely to be chosen.11 Adoption still lags. One 2025 survey found that 70% of marketers expected AEO to reshape their strategy, but only 20% had started doing it.15

Measurement and the opt-out question

Businesses now have better tools for measuring AI visibility. On August 31, Google's generative AI performance reports in Search Console became available to every site worldwide.7 Merchant Center has a matching report for retailers covering shopping journeys that start in AI Mode, AI Overviews or Gemini.8 Researchers warn that AI answers change with wording, location and model updates, so measurement based on single prompts is unreliable.19

Google also added a Search Console setting that removes a site from AI Overviews, AI Mode and AI Overviews in Discover. The trade-off is that opted-out sites get no traffic or impressions from those features.2 Its pilot program paying publishers for AI use of their content is small. For several small and midsize sites, the payments came to less than one-tenth of 1% of advertising revenue.1

The bottom line

The urgency is real, but it is not the urgency of a new technical trick. Google is turning AI answers into the default first screen for a growing share of queries. Rigorous studies show that this reduces clicks to the open web.925 For most businesses, opting out means becoming invisible, and ranking alone no longer guarantees a citation. That leaves one strategy that holds up: produce distinctive, evidence-rich content that a model wants to quote, and measure AI citations as closely as rankings were once measured.