What AI engines cite when buyers ask what to buy

Key findings

• Google's AI leans on YouTube and Reddit. ChatGPT doesn't. Google AI Overviews cited YouTube in 85% of its answers and Reddit in 48%. ChatGPT cited YouTube once and Reddit 3 times in 5,986 citations.
• The engines rarely agree. On average, 71% of the sites cited for a question were cited by only one of the four engines. Only 106 of 298 questions had even one site that all four cited.
• Ask twice, get different sources. Asking the same engine the same question twice, the two answers shared 46% of their cited sites on average. ChatGPT never cited exactly the same set of sites twice (0 of 298 questions).
• Engines cite roundups. 67% of cited pages had “best”, “top”, “vs”, “alternatives”, “compare” or “review” in the title. For Gemini it was 95%.

According to aivisibilityskill's analysis of 24,258 citations, 71% of the websites AI engines cite for a buyer question are cited by only one engine. Checking one engine, once, shows you a small and unstable slice of what buyers see.

aivisibilityskill, What AI engines cite, 300 questions × 4 engines × 2 samples, October 29 to November 1, 2026

How we collected the data

We asked 300 buyer questions about software, such as “best accounting software for small business”, “1password vs bitwarden” and “ahrefs alternatives”, to ChatGPT (with web search), Gemini, Google AI Overviews and Google AI Mode. Each engine got each question twice, in US English, without any account history. Answers were collected between October 29 and November 1, 2026, through the same pipeline the product uses.

A citation is a link the answer shows as a source. We counted websites by domain, with “www.” removed. Gemini answered 587 of its 600 prompts and Google showed an AI Overview for 594 of 600; the rest are excluded.

Limits: software categories only, one country and language, a four-day window, and two samples per question. Treat the numbers as a snapshot of how these engines behave for software buyers, not a law.

Each engine, side by side

Gemini cites the most sources per answer, and nearly all of them are roundups. Google's two AI surfaces behave alike, and differently from ChatGPT: video and forum threads for Google, written roundups for ChatGPT.

The sites cited most

Two things stand out. First, general-purpose sites (YouTube, Reddit) dominate because Google's AI uses them so heavily. Second, a handful of roundup publishers carry a lot of weight: itechguides.com appeared in 114 answers, all of them ChatGPT's. If a roundup like that leaves you out, the engine that relies on it probably will too.

What to do about it

1. Check more than one engine, more than once. With so little overlap, a single ChatGPT chat tells you little. Measure how often you're named across engines and samples. Here's how.
2. Find the roundups that decide your category. Look at which pages the engines cite for your buyers' questions, then get onto those lists or publish an honest comparison page of your own.
3. For Google's AI, think beyond your website. A clear YouTube walkthrough and real answers in the Reddit threads Google cites can matter as much as your own pages.
4. Make sure the crawlers can read you. If OAI-SearchBot or PerplexityBot is blocked, the engines can't cite you however good the page is. See which AI crawlers to allow.

Cite this study

You're welcome to use these numbers. Please link to this page: aivisibilityskill (2026). What AI engines cite. https://aivisibilityskill.com/guides/what-ai-engines-cite