ChatGPT and Perplexity Barely Cite the Same Websites
New research found only 11% overlap between which sites ChatGPT and Perplexity cite. Here's why, and what it means for your strategy.
New 2026 research looked at millions of AI citations and found that only about 11% of websites get cited by both ChatGPT and Perplexity. Reddit alone makes up about 40% of citations across the major AI engines. If you're treating "AI search" as one single target, this data says that's the wrong way to think about it.
- Only about 11% of websites are cited by both ChatGPT and Perplexity.
- Perplexity cites about 22 sources per answer on average. ChatGPT cites about 10.
- Reddit makes up roughly 40% of citations across the major AI engines.
- Wikipedia alone makes up 26-48% of ChatGPT's citations specifically.
- The top 60 websites combined make up about 68% of every citation across ChatGPT, Claude, Gemini, Perplexity, and Google AI Overviews.
How much do ChatGPT and Perplexity actually agree on?
Not much. If two AI tools are both pulling information from the open web, you'd expect them to land on a lot of the same sources. They don't. About 89% of the sites cited by one are never cited by the other. They're pulling from genuinely different pools of sources, not the same pool with a different order on top.
| Metric | ChatGPT | Perplexity |
|---|---|---|
| Average sources cited per answer | 10.4 | 21.9 |
| Overlap with the other engine | ~11% shared |
Why does Reddit show up so often?
It's not because Reddit has high "authority" the way a big news site might. It's because a Reddit thread often has several different people confirming, or arguing about, the same fact in one place. That's exactly the kind of thing an AI model likes to see before it repeats a claim confidently. Wikipedia works the same way, just in a more organized format.
If you're building one strategy for "AI search" instead of separate ones for the tools your audience actually uses, this is exactly the gap that's costing you visibility.
Does Perplexity cite more sources than ChatGPT?
Yes, roughly double. Perplexity pulls in about 22 sources per answer, ChatGPT pulls in about 10. That has a real effect on strategy:
- Getting cited by Perplexity is a slightly lower bar, since more sources make it into each answer.
- Getting cited by ChatGPT likely carries more weight per citation, since fewer sources make the cut.
What should you do with this data?
Don't treat "AI search visibility" like one single goal. Split your thinking:
- For ChatGPT, focus on the same fundamentals a full AEO & GEO audit already checks: clear structure, named sources, direct answers. ChatGPT's citation list is tighter and leans toward well-established, well-checked sources.
- For Perplexity, just showing up matters more, since more sources make it into each answer.
- For both, a real presence on community sites like Reddit (even without a link back to you) is doing real work, since that's where a big share of citations already come from.
Is this data likely to change?
Probably, and often. AI engines change how they pick sources fairly regularly, so treat this as a snapshot of late 2026, not a permanent rule. Still, the core idea (different engines pull from different pools) is unlikely to disappear soon.
FAQ
Should I only optimize for one AI engine?
No. The on-page basics (clear structure, named sources, direct answers) help across every engine. What changes is which sources actually get pulled in for each one.
Why does Reddit get cited so much across every AI engine?
Not because of authority, but structure. A Reddit thread often has multiple people independently confirming or debating the same fact in one place, which is exactly what a model looks for before repeating a claim confidently.
Is 11% overlap surprising?
Yes, compared to the common assumption that AI tools pulling from the same open web would land on similar sources. This data shows they don't.
Does Perplexity citing more sources mean it's easier to get cited there?
It's a lower bar to get included, since more sources make it into each answer. But each individual citation likely carries less weight than a ChatGPT citation, since ChatGPT's list is shorter.
Where does this data come from?
A 2026 citation research index that studied citation patterns across ChatGPT, Claude, Gemini, Perplexity, and Google AI Overviews. See the source link at the end of this post.