# AI engines barely overlap — route per engine

**Confidence: [M]** (680M-citation analysis; vendor methodology)

Only ~**11% of cited domains overlap between ChatGPT and Perplexity**. Each
engine is its own ecosystem:

| Engine               | Retrieval backbone          | Distinct lever                             |
| -------------------- | --------------------------- | ------------------------------------------ |
| Google AI Mode / AIO | Google index + core ranking | entity authority, info gain, GBP           |
| ChatGPT Search       | Bing index + OAI-SearchBot  | Bing Webmaster Tools ([[bing-is-chatgpt]]) |
| Perplexity           | own index, Reddit/UGC-heavy | Yelp, niche directories, Reddit presence   |
| Gemini               | Google + GBP local data     | profile accuracy (best local recs)         |
| Claude               | Brave + Claude-SearchBot    | structured deep content                    |

**How to apply:** a single "AI visibility" number is meaningless — sample
citation share per engine on priority queries, and invest per-engine where
the audience is. One Google parameter change once dropped ChatGPT's Reddit
share 60%→10% in six weeks — the mix is volatile; re-sample, don't assume.

**Evidence:** https://authoritytech.io/curated/ai-citation-11-percent-platform-overlap-per-engine-audit-2026 ·
https://discoveredlabs.com/blog/chatgpt-claude-perplexity-and-google-ai-overviews-how-each-platform-cites-sources-differently
