PolyComparisonAbout PolyComparison
PolyComparison is a small, on-demand explorer for prediction markets — paste a Polymarket or Kalshi link and instantly see how the other platform prices the same real-world question, in the spirit of an Etherscan or CoinMarketCap page, but for prediction markets.
How it works
- 01Paste a Polymarket or Kalshi market link.
- 02The server resolves it against the platform's public API and normalizes price, volume, liquidity, spread, and resolution date into one shared shape.
- 03It searches the other platform for the closest matching market and shows a ranked list of candidates.
- 04You get a side-by-side comparison — probability gap, volume difference, resolution-date gap, and a one-line verdict on which platform offers the better price to buy Yes.
How matching works
Neither platform's data schema knows about the other, so matching is a two-stage hybrid, not a guarantee: a fast, free heuristic shortlist ranks candidates by title similarity, then a small AI model (gpt-5.4-mini) re-ranks ambiguous cases by judging whether two markets are actually about the same underlying event — not just sharing keywords. If no OPENAI_API_KEY is configured, matching falls back to the heuristic alone. The UI always shows the next-best alternatives, so you can override the pick either way.
Data sources
All data is fetched live from each platform's public, unauthenticated market-data API — no scraping, no private endpoints, no stored history.
PolyComparison is not affiliated with, endorsed by, or built using non-public data from Polymarket or Kalshi.
Open source
Both the web app and its CLI sibling are open source under the same author.