How Google Chooses the Sources Gemini and AI Overviews Cite

Gemini and Google AI Overviews cite you in one of two ways: Google's systems pull up your page as evidence, or the third-party pages they pull up describe you accurately.

Google's guide to optimizing for generative AI features, last updated on 10 July 2026, is blunt: from Google Search's side, optimizing for AI search is still SEO. OnlyAEO is an AEO and GEO agency.

How does Gemini decide which pages to cite?

Gemini cites the pages it found when it searched Google during the answer, a process Google calls grounding.

The Gemini API documentation on grounding with Google Search says grounding connects the model to real-time web content so it can cite verifiable sources beyond its knowledge cutoff. The steps:

1. The model decides whether a Google Search would improve the answer.
2. If so, it writes its own search queries and runs them.
3. It writes the answer, tying each citation to the text that source supports.

In Google's example, given the prompt "Who won the euro 2024?", the model searched for "UEFA Euro 2024 winner". The line that Spain beat England 2-1 in the final went to Al Jazeera, and the line about Spain's record fourth European Championship title went to uefa.com.

• The model's wording counts. Its query was shorter and more formal than the person's, so your page competes for the model's wording.
• Credit went sentence by sentence. Each source won a single, plainly stated fact, and both were the obvious authorities for it.

Google's Gemini Apps help page says the app shows sources only sometimes, within and below a response.

Do AI Overviews and the Gemini app choose sources the same way?

AI Overviews and the Gemini app draw on the same Search index, but they are separate products with separate controls.

How AI Overviews pick sources

Google's overview of AI Overviews and AI Mode says AI Overviews use a customized Gemini model working with Search's ranking systems and the Knowledge Graph. They are built to surface information backed by top web results, with links to supporting content.

Google's page on AI features and your website says AI Overviews and AI Mode may use query fan-out, issuing related searches across subtopics. Google says its models find more supporting pages while generating the response, so it can show a wider, more diverse set of links than classic search.

An April 2026 arXiv study found a related pattern: Google and Perplexity cited more sources on average than ChatGPT.

Where the controls split

Google's crawler documentation describes the Google-Extended robots.txt token:

• Gemini model training. It decides whether your content may train future Gemini models.
• Gemini app grounding. It decides whether your content may be used for grounding in the Gemini app.
• Not Google Search. It does not affect your inclusion in Google Search.

Block it to stay out of training and you also stop your pages grounding Gemini app answers, while AI Overviews can keep citing you. Make that choice on purpose.

For AI Mode, a third surface, read why Google AI Mode is a different beast.

How we tested

On 13 October 2026 we asked Gemini (gemini.google.com, signed out, default model) and Google Search the same question: "What is the best CRM for a small B2B SaaS company?"

Gemini named HubSpot CRM, Pipedrive, Close, Zoho CRM and Attio. Every citation chip under its answer credited the same page, a CRM comparison article published by a marketing agency that works with SaaS companies.

A few chips also credited another CRM roundup aimed at startups. None credited the website of any CRM vendor it recommended.

The AI Overview for the same search named a similar group (HubSpot CRM, Pipedrive, ActiveCampaign, Attio and Zoho CRM). Its visible source links were a pair of Reddit threads asking which CRM suits a SaaS business, plus that same agency article.

Vendor pages, including HubSpot's blog, Freshworks and monday.com, ranked in the regular results on the same page but were not among the visible AI Overview sources. Some chips had more sources folded away that we did not open, so we report only what was visible.

This is a single question on a single day, and answers change from run to run and from user to user. Treat it as an illustration of where Google's AI looked, not a measurement.

If Google cites third-party pages, where does your brand need to appear?

Your brand needs to appear, described accurately, on the comparison articles, roundups and forum threads Google's AI already reads for your category.

Google's guide says its AI features can show what is said about products and services in blogs, videos and forum discussions, and that seeking inauthentic mentions is not as helpful as it might seem. So skip the planted Reddit comments and earn an accurate place on the cited pages:

1. Find the pages cited for your category.
2. Give each author better data.
3. Correct what is out of date.
4. Contribute where you have real standing.

Our earn-citation list is a ranked list of third-party sites AI cites in a brand's space where the brand is not mentioned yet, with a recommended play per site (guest post, partnership, listing or review). It cannot make an editor say yes.

Our guide to the earned media sources AI cites covers where to start.

What does Google require before it can cite your pages?

Google requires a page to be indexed and eligible to appear in Google Search with a snippet, meeting the normal Search technical requirements. The site must also be included in Search generative AI features in Search Console.

The Search generative AI control

The control sits in Search Console under Settings > Search generative AI. Inclusion is the default, and Google rolled the control out to all websites as of August 31, 2026.

Excluding your site removes your links and content from AI Overviews, AI Mode and generative AI features in Discover, with no traffic or impressions from them. Training is handled separately, by Google-Extended. If your pages vanish from AI Overviews overnight, check this setting first.

Crawling and preview controls

Google lists allowing crawling in robots.txt, and in any CDN or hosting layer, among the SEO practices that still apply to AI features. Our post on the robots.txt mistake that blocks AI crawlers covers the usual errors.

Google names nosnippet, data-nosnippet, max-snippet and noindex as the ways to limit what is shown from a page. Its robots meta tag documentation adds detail:

• nosnippet blocks direct input. It also stops a page being used as a direct input for AI Overviews and AI Mode.
• max-snippet sets a limit. It also limits how much of a page can be used as a direct input for AI Overviews and AI Mode.
• data-nosnippet is selective. It works on span, div and section elements, so you can hold back one block and leave the rest of the page eligible.

None of this guarantees inclusion: Google's guide says indexing and serving aren't guaranteed, even for a page that meets every requirement.

What does Google say earns a citation?

Google's answer is content that adds something other sources lack. Its guide says unique, compelling and useful content will likely influence your presence in generative AI search in the long run more than any of its other suggestions. Since its systems look across many sources, a standout viewpoint can help, such as a first-hand review based on personal experience.

The guide's example of commodity content is a page called "7 Tips for First-Time Homebuyers", which is often based on common knowledge. Non-commodity content offers an expert or experienced take: for a B2B SaaS brand, implementation data, pricing logic and the cases where your product is the wrong fit; for an e-commerce brand, real product testing and sizing data.

How to build the page

• Use clear headings. Organize pages into sections under headings that give a clear structure.
• Add images and video. Google's AI features can bring those in, which gives you more ways to appear than a text link.
• Connect feeds and profiles. If you sell products or serve a local area, Google says Merchant Center feeds and Google Business Profiles can help your products and services appear in AI responses and other Google Search results.

What the arXiv study adds

The study's authors analyzed 602 controlled prompts across ChatGPT, Google AI Overview and Gemini, and Perplexity. Those prompts covered 21,143 valid search-layer citations.

High-influence pages tended to be longer, more structured, semantically aligned with the question, and richer in extractable evidence such as definitions, numerical facts, comparisons and procedural steps. The finding is a correlation in a single dataset, but it fits Google's advice.

What does Google say you can skip?

Google lists several tactics you can ignore for Google Search, most of them in its optimization guide. Its FAQ and HowTo changes also undercut older schema advice.

Google's August 2023 post on HowTo and FAQ changes is the source for the last rows. Keep the structured data that earns rich results, matched to the visible text on the page.

How does Google know which company you are?

Google records companies as entities in its Knowledge Graph, which the Gemini model behind AI Overviews works with. A model unsure who you are may name someone it is sure about.

Knowledge panels

Google's page about knowledge panels says they appear for entities in the Knowledge Graph and are generated automatically from sources across the web.

If a panel exists for your company, its subject or an official representative can claim it and suggest changes through Google's verification process.

Organization markup

• It can aid disambiguation. Google's Organization markup documentation says it can help Google understand your details and disambiguate you in search results.
• It can shape your logo. Some properties can influence which logo appears in Search results and your knowledge panel.
• One page is enough. Put it on the home page or about page, not every page.
• sameAs lists your profiles. Use it for your profiles on other sites, such as social and review profiles.

Keep the markup identical to those profiles: same name, spelling and description.

Check what Gemini says about you

Ask Gemini, signed out, what your company is, what it sells, and who its competitors are. Check the answer is current and has not mixed you up with a namesake.

If it confuses you with a namesake, start with the basics above: one name, matching Organization markup and consistent outside profiles. For Wikidata and Knowledge Graph steps, see how to build a brand entity AI engines recognize.

How do you measure whether Gemini and AI Overviews cite you?

Measure AI Overviews and AI Mode in Search Console, and check the Gemini app by hand, more than once. Google says traffic from AI Overviews and AI Mode is counted in the Performance report under the Web search type.

AI Overviews and AI Mode in Search Console

The Generative AI performance report reached all websites as of August 31, 2026.

• AI impressions. It covers impressions from AI Overviews and AI Mode.
• Counting rule. An impression is counted each time a link to your site was shown.
• Row limit. The report has the usual 1,000 row limit.
• Report dimensions. Page, country, date and device, so it shows which pages appeared, not what the answer said about you.

The Gemini app, by hand

Search Console does not cover the Gemini app. Our step-by-step guide to measuring AI visibility has the full method; in short:

1. Run your buyers' real questions in Gemini and Google Search.
2. Record which pages each answer cites and how it describes you.
3. Repeat each run, because answers vary.

Google states that no third-party tool has access to its internal ranking or AI systems. Every tracker, ours included, samples answers from outside.

OnlyAEO's platform can run ChatGPT, Claude, Gemini (Flash and Pro), DeepSeek and Grok, with ChatGPT, Claude and Gemini on by default with web search, and every prompt runs twice per engine.

How long does it take, and what should you ask of an agency?

First measurable results usually take at least 60 days. OnlyAEO does not guarantee results or promise specific rankings or citations.

For scale: for a New York edibles retailer, AI visibility went from 1.5% (#50) to 25%, #4 of 374 brands, and the retailer's own website became the most-cited source in its category, ahead of New York State's official site.

The case study reports AI visibility, not a Gemini-specific figure. The full write-up is on our case studies page.

When you choose an agency, ask:

1. Does the advice trace back to Google's documentation, or to lift tables nobody can source?
2. Do they test your buyers' real questions more than once?
3. Does the plan add first-hand material, or pages at volume built to manipulate rankings, which Google treats as scaled content abuse?
4. Do they work the third-party pages that actually get cited?

Our answer: before writing, we ask ChatGPT and Claude the buyer's question, read every page they cite in full, and turn each search they ran into a section of the article. Each buyer persona is researched from the brand's market, because each persona gets a different answer.

More is on how OnlyAEO works. Google's guide covers Google only. As Search Engine Journal noted, it does not settle the debate for platforms like ChatGPT or Perplexity, which may weigh signals differently.

Frequently asked questions

If I exclude my site from Search generative AI features, do competitors fill the gap?

Yes. Google says content from other sites stays available in those features and may look similar to yours. The exclusion is not used as a ranking or inclusion signal for the rest of Google Search, so it does not count against your regular results.

Does the Generative AI performance report include Discover or Search Labs?

No. Google's help page for the report says Discover has its own generative AI performance report in Search Console, and Search Console does not include data from Search Labs experiments.

Can Gemini cite something other than a public website?

Yes. Google says source links in Gemini Apps can include public websites, files the user uploaded, or Google Workspace documents and emails when Workspace is connected.

What extra details can a merchant control in Google's brand panel?

Google's Organization markup documentation says merchants can influence more details in their merchant knowledge panel and brand profile, including return policy, address and contact information. Keep those details consistent with your Merchant Center account.

Why does an AI Overview appear for some buyer questions and not others?

Google shows an AI Overview only when its systems judge it additive to classic Search, so for many queries one does not trigger. Google also says AI Overviews and AI Mode may use different models and techniques, so the set of responses and links they show will vary.