TLDR
Similarweb data shows AI answer boxes appeared on more than 40 per cent of US Google searches as of May 2026, up from around 15 per cent in January 2025, a shift that unfolded across sixteen months, not a single year. Monthly visits to Google's conversational AI Mode nearly doubled, rising from 126 million in June 2025 to 279 million in May 2026. A separate study tracking trending queries found that question-form searches trigger AI answers almost two thirds of the time. Australian businesses still budgeting for search as though AI answers are a fringe feature are likely misreading where most queries now land.
KEY TAKEAWAYS
From occasional feature to the normal Google experience
Sixteen months ago, Google's AI answer boxes were an experiment most Australians could scroll past without noticing. Similarweb's mid-2026 generative AI landscape report put AI Overviews on more than 40 per cent of US Google searches by May 2026verifiedVerified Source: similarweb.com, compared with roughly 15 per cent in January 2025.[1] They are now the default experience for a large share of searches.
The sixteen-month timeframe matters. A business that benchmarked the feature in early 2025 and decided to revisit it next financial year has already watched the share nearly triple, because the rollout was not a single event but a sustained, compounding expansion.
The numbers, and why the trackers disagree on the exact share
BrightEdge, monitoring its own pool of client queries, recorded AI Overviews on roughly 48 per cent of searches it tracked in February 2026.[3] A peer-reviewed study published on arXiv in May 2026, which analysed 55,393 trending queries between 13 March and 21 April 2026, found an average activation rate of 13.7 per cent across that broader, trend-skewed sample.[4] No two tracking firms land on the same figure, and the gap reflects methodology, not error.
BrightEdge monitors commercial and informational queries typical of enterprise clients, while the arXiv study drew on trending searches that skew toward news and entertainment topics where Google is more conservative about inserting AI answers. For question-form queries specifically, the academic study found AI Overview activation reached 64.7 per cent during that same March, April 2026 windowverifiedVerified Source: arxiv.org, a figure that aligns the trackers on the point that matters most: if a user types a question, they will almost certainly see an AI answer before any blue link.[4]
The direction of travel is consistent across every source. What the exact number is matters less than what it is doing: rising fast, with no sign of reversal.
What the shift means for a business that relies on search traffic
Google's AI Overview synthesises information from multiple pages and delivers an answer directly on the results page. A user who gets a satisfactory answer there has no reason to click, so holding the top organic position still has value, but a different kind of value than it had in 2023: visibility without clicks, unless your brand is the one the answer box cites.
Shivani Mohan, Vice President of Data Science and UXR at Google, said "AI Mode isn't just changing how people search, it's expanding the very definition of what's searchable."verifiedVerified Source: blog.google[5] Monthly visits to Google's AI Mode rose from 126 million in June 2025 to 279 million in May 2026, according to Similarweb's tracking of the product's standalone conversational interface.[2] Conversational search is no longer a niche behaviour.
Rand Fishkin, co-author of Zero Click Marketing and founder of SparkToro, said that AI influence is clearly happening and that marketers need a new way to measure and attribute that impact.[1] The old model of tracking rankings, counting clicks and reporting sessions does not capture whether a brand is winning or losing in an answer-box world.
Being the source the answer is built from
When Google's AI Overview cites a page, it draws authority from that page to construct an answer and places a visible source link below the answer box. Brands cited there receive implicit endorsement from the search engine itself; brands that are not cited are invisible, regardless of their ranking position.
The practical question for any business is whether its content is structured and substantive enough to be pulled into an answer synthesis. Thin product descriptions, generic landing pages and content written primarily to rank for a keyword are less likely to be cited than pages that directly and completely answer a specific question. The academic research found that longer, more authoritative pages were disproportionately represented in AI Overview citations, consistent with Google's long-said preference for expertise and depth.[4]
What Australian businesses should do now
The Similarweb data is US-based, and Google's rollout of AI Overviews in Australia has lagged the US by several months at each expansion stage. That lag is not a reason to wait; it is a window to act before the feature reaches the same saturation locally that it has already reached in the US market.
Businesses that depend on organic search, whether for leads, e-commerce traffic or brand discovery, need to audit which of their pages address genuine questions and whether those pages provide complete, citable answers. A page that ranks third for a keyword but provides the clearest, most structured answer to a related question is more likely to appear in an AI Overview than the page currently sitting in the top spot. BrightEdge's February 2026 tracking recorded AI Overviews on roughly 48 per cent of its monitored query set, a share that has likely grown further since that measurement was taken.[3]
SOURCES & CITATIONS
FREQUENTLY ASKED QUESTIONS
What is a Google AI Overview?
How fast have AI Overviews spread on Google?
Do all queries trigger an AI Overview?
Does this affect Australian businesses if the data is from the US?
Jonas Valenti writes about search and how businesses get discovered. He has spent years watching what makes a company visible online, and is unsentimental about tactics that no longer work.
