We Asked 4 AI Engines 101 Buyer Questions. They Almost Never Agreed.
Quick answer: We ran 101 real buyer questions across ChatGPT, Perplexity, Gemini and Claude and recorded every source each one cited. The engines disagreed on the top source 70% of the time, leaned on 1,811 different domains, and pulled in Reddit for nearly every question. Here is the data, and what it means for getting cited.
⚡ Key takeaways
- → Across 101 buyer questions, the four engines named the same top source 0% of the time, and on 70% no two even shared a top source. Tracking one engine is not tracking AI.
- → AI answers are heavily source-backed: 95–100% of answers cited a source, so being a cited source is the game, not an extra.
- → Engines pulled from 1,811 different domains across the run, about 31 distinct sources per question. There is no short list to win.
- → Reddit showed up in the sources for 96% of questions, YouTube for 81%. Community and video punch far above their weight.
Everyone has an opinion about how to "get cited by AI." We had the tooling to just measure it, so we did. In June 2026 we ran 101 real buyer questions across ChatGPT, Perplexity, Gemini and Claude, with web search and grounding on, and recorded every source each engine cited. The result is a snapshot of what the citation landscape actually looks like, rather than another round of guessing.
The short version: the engines disagree far more than people assume, they cite almost constantly, and they lean on a sprawling, fragmented set of mostly third-party sources, with Reddit and YouTube turning up nearly everywhere.
The engines barely agree on anything
This was the headline. For each question we took the top source each engine cited and compared them.
- On 0 of 101 questions did all four engines name the same top source.
- On 71 of 101 (70%), no two engines even shared a top source.
In other words, the "best source" for a question according to ChatGPT is usually not the one Perplexity, Gemini or Claude picks. If you watch a single engine and call it your AI visibility, you are seeing roughly a quarter of the picture at best.
Top-source overlap across the four engines
All four engines agreeing on the top source happened on 0% of the 101 questions.
They cite constantly, and at different depths
Every engine backed its answers with sources almost every time, but how many sources, and how deep, varied a lot.
| Engine | Answers that cited a source | Avg sources per answer |
|---|---|---|
| Perplexity | 100% | 8.8 |
| Claude | 100% | 10.7 |
| Gemini | 97% | 14.3 |
| ChatGPT | 95% | 5.6 |
Average sources cited per answer
Two things stand out. First, citation is not occasional, it is the norm, so the question is never "will AI cite a source," it is "will it be you." Second, Gemini reaches for more than twice as many sources per answer as ChatGPT, which means breadth of credible mentions matters more for some engines than others.
There is no short list to win
If you were hoping to "get on the five sites AI trusts," the data is blunt: there is no such list. Across the run the engines cited 1,811 unique domains, and a typical question pulled in about 31 distinct sources across the four engines. The citation pool is wide and fragmented, which is good news and bad news, there is no gatekeeper to bribe, but there is also no shortcut. You earn citations topic by topic.
That said, a few sources recur far more than the rest:
Most-cited domains (citation count, all engines)
Reddit and YouTube are almost everywhere
Even though no single domain dominates the raw count, two show up with striking consistency across questions:
- Reddit appeared in the cited sources for 97 of 101 questions (96%).
- YouTube appeared for 82 of 101 (81%).
So while your competitors argue about schema, the engines are quietly leaning on a Reddit thread and a YouTube video for almost every buyer question. If your category has neither an honest Reddit presence nor video coverage, you are absent from the sources the engines reach for most reliably.
What this means if you want to get cited
A few practical reads, straight from the numbers:
- Track every engine, not one. With zero full agreement and 70% no-overlap, a single-engine view is noise. Measure ChatGPT, Perplexity, Gemini and Claude together.
- Earn credible third-party mentions, not just on-page polish. The citations live across review sites, editorial roundups, Reddit and YouTube, far more than on any one brand's own pages. That is GEO, and it is mostly off-site.
- Show up on Reddit and YouTube honestly. They are in the sources for the overwhelming majority of questions. A genuine presence there is table stakes now.
- Watch breadth for Gemini. Engines that pull 10–14 sources reward being one of many credible mentions, so volume of accurate coverage matters.
The throughline: you cannot manage this from a single dashboard glance or a one-time audit. The picture is fragmented, it differs per engine, and it shifts. Measuring it continuously is the only way to know where you stand, which is the whole reason CiteTrack AI tracks citations across engines and maps the sources behind each answer.
How we ran it, honestly
We sent 101 real buyer questions, spanning AI search, WordPress, ecommerce and adjacent SaaS categories, to ChatGPT, Perplexity, Gemini and Claude in June 2026, each with web search or grounding enabled, using our own API keys. For every answer we recorded the sources the engine cited, then computed citation rates, per-question source overlap, and the domain leaderboard.
Two honest caveats. We did not include Microsoft Copilot, because it has no comparable public answer API. And "top source" means the first source an engine cited for a question, a reasonable proxy for what it leaned on most, not a claim about ranking weight inside the model. The figures are a dated snapshot, not a permanent law, which is exactly why we treat measurement as ongoing.
Frequently asked questions
How often do AI engines cite the same source?
Rarely. In our June 2026 run of 101 buyer questions across ChatGPT, Perplexity, Gemini and Claude, all four named the same top source on 0% of questions, and on 70% no two engines shared a top source.
Do AI answers actually cite sources?
Almost always. Citation rates were 95% (ChatGPT), 97% (Gemini), 100% (Perplexity) and 100% (Claude). Being a cited source is the norm, so the real question is whether the source is you.
Which sites get cited most by AI?
The pool is fragmented, 1,811 unique domains across the run, but YouTube, Reddit and review/comparison sites (TechRadar, G2) and editorial roundups (Zapier, WPBeginner) recur most. Reddit appeared in the sources for 96% of questions and YouTube for 81%.
Should I track more than one AI engine?
Yes. Because the engines disagree on the top source 70% of the time, tracking one gives you a fraction of the picture. Measure ChatGPT, Perplexity, Gemini and Claude together.
Related reading
- How to Track Whether AI Is Citing Your Site
- Best Tools to Track AI Citations
- Complete Guide to GEO
- AI Citation Tracking for WordPress
- AI Search Statistics 2026
- Free tool: AI-Readiness Grader
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