What Is an AI Overview? How Google Picks Its Sources (2026)

A Google AI Overview is a short AI-written answer Google puts above the regular results for some searches, linking the pages it drew on. It is the public successor to the 2023 Search Generative Experience (SGE) test, available to all users in supported countries, and searchers can't turn it off. Site owners, though, gained an opt-out in Search Console in 2026.

What is an AI Overview?

An AI Overview is a generated summary at the top of the results page that answers a query in a few lines and links to the pages behind it. Google shows one only when its systems judge it adds something beyond classic results, so many searches never get one.

How often? In a May 2026 arXiv preprint, 55,393 trending US English queries run in March and April 2026 produced an AI Overview 13.7% of the time, and 64.7% of the time when phrased as questions. Trending queries aren't your keywords; read that as a direction.

There is nothing to buy. Google lists AI Overviews as available to all users and dropped the sign-in requirement in March 2025. It reported over 2.5 billion monthly active users in June 2026.

What happened to SGE?

SGE, the Search Generative Experience, was Google's opt-in Search Labs test of AI answers in Search. Google released the same idea to everyone in the US as AI Overviews in May 2024, and the SGE name faded while the feature stayed.

Google's launch post never says "SGE", but notes billions of uses in a Search Labs experiment, and TechCrunch tied that experiment to SGE the same day. SGE already showed links and took follow-up questions, which AI Mode later expanded.

Our advice: don't optimize for a product name. The labels changed; the core loop stayed: retrieve pages from Search, write a synthesis, link the sources. To spot the next experiment early, watch the AI Mode opt-in in Search Labs.

How do AI Overviews choose their sources?

Google says AI Overviews retrieve pages through its normal Search ranking systems, may fan one query out into several related searches, then write an answer grounded in those pages and link them. A page is eligible if it is indexed, can show a snippet, and sits on a site not excluded in Search Console.

Google's example: a question about fixing a weedy lawn can fan out into searches for herbicides, chemical-free removal and prevention. There are no extra technical requirements, and Google says it ignores llms.txt files and needs no special markup, chunking or AI-specific rewriting. It asks for unique, non-commodity content. We write answer-first for readers, not because Google requires it.

Cited pages are not simply the top results. In the preprint, 29.8% of cited domains were absent from the first results page for the same query, only 41.4% matched a top-ten result, and the median Overview carried 8 references.

Our read: a top-ten ranking is neither required nor sufficient. With fan-out, the cited page is often the clearest answer to a sub-question, not the head query's top result. Cited domains also scored higher on a credibility scale than the page-one domains beside them.

Thin topics are where retrieval turns odd. Google explained its May 2024 "eat rocks" answer as a data void: with almost no serious content, the Overview linked one of the few pages on the question, a satirical one. Where good answers are scarce, one clear, accurate page can become the source.

How are AI Overviews different from featured snippets and AI Mode?

A featured snippet quotes one passage from one page. An AI Overview writes a new summary from several pages and links them. AI Mode is a separate, conversational experience that searches subtopics, and every follow-up runs new searches.

Since 19 May 2026 a follow-up asked inside an AI Overview continues in AI Mode, blurring the line for users. For site owners the rules are shared: the same indexed, snippet-eligible page, one Search Console control, one report. Tactics specific to AI Mode are in our AI Mode playbook.

Can you opt out of AI Overviews, and should you?

As of October 2026, searchers can't turn AI Overviews off: Google calls them a core Search feature, and the Web filter, chosen after a search, shows text links without them. Site owners got a real control in 2026, the Search generative AI control in Search Console, but most brands should leave it on.

Leave the control on if you sell something other than the page view. Excluding your site removes your links from the answers your buyers read, while similar content from other sites stays. Publishers who live on pageviews face a real trade-off; read the new report first. Click studies are in AI Overviews and your traffic.

People reach for Google-Extended first, and it is the wrong lever. Google says it governs training and grounding in Gemini products and does not affect inclusion in Google Search; appearing in AI Overviews is the Search Console control's job.

In AEOeye's crawler access study (3 October 2026), 31 of 384 sites (8.1%) blocked it from their homepage: 20 of 38 news publishers, 5 of 20 UGC and review sites, 4 of 90 e-commerce and consumer brands, 2 of 193 SaaS brands and none of 43 AI-visibility vendors. And 30 of those 31 still let Googlebot fetch their homepage, so as far as robots.txt shows they remain open to AI Overviews. Training and appearing are separate decisions with separate switches.

Treat that as a snapshot, not a census: a convenience sample of well-known sites, fetched once from the main host, with per-site data public. aeoeye.com's own robots.txt allows Google-Extended and the other major AI crawlers, because our business is being found. More on each bot is in our AI crawler user-agent directory.

How do you know whether you appear in AI Overviews?

Open the generative AI performance report in Search Console. It shows how often your pages appeared in AI Overviews and AI Mode, by page, country, device and date, and Google says it reached all websites by 31 August 2026.

1. Check impressions. The report counts impressions; clicks still sit in the main Performance report.
2. Spot-check by hand. Search your buyers' questions in a private window, in their country and language, with several phrasings. A comparison of generative search systems found outputs vary across time and repeat runs, so one screenshot proves little.
3. Read what it says about you. A link isn't an endorsement of the paragraph beside it: in the preprint's automated check, validated against human labels, 11.0% of 98,020 claims weren't supported by the pages cited, usually because the page never addressed them.
4. Test the other engines. No third-party tool sees inside Google, as Google itself points out, and ours doesn't either. We can ask the engines your buyers use: our free audit at AEOeye puts three unbranded buyer questions to ChatGPT and shows the full answers; the $29 full report adds Google AI, Gemini, Claude and Perplexity.

To act on what you find, start with how to rank in AI Overviews and what triggers one.