Analytics & dataAPIfree
PolymarketData: what it does, what it costs, where it stops
Last checked 2026-09-08
PolymarketData is a historical data service for Polymarket. It stores minute-level prices, market metrics and L2 order book snapshots and serves them through a REST API, a Python SDK and bulk S3 exports.
It is built for quants and researchers rather than for browsing. The site lists 19B+ rows across 1M+ unique markets and names academic users at LSE, Cornell, Yale, Boston University and Bocconi.
What it does
Three endpoint families: prices, metrics (liquidity, spread and related tradeability signals) and books (historical L2 order book snapshots for execution and slippage simulation). Minute snapshots run from August 2025 onward.
Historical endpoints lag live markets by under 2 minutes, so open markets are queryable as data accumulates. Cancelled and voided markets are included and tagged.
- Delivery: REST API, Python SDK, S3 dumps in Parquet, CSV or JSON, one-time or scheduled
- Custom exports filtered by time range and category
- Full series, event and market hierarchy with resolution outcomes
Pricing
Four self-serve plans, all monthly. Free: 10-minute time series, last month of data, historical prices and volume, no order books, 10 requests per minute. Trader at $60: 1-minute data, last month, historical order books, 100 RPM. Pro at $120: 1-minute data, last 3 months, order books, 500 RPM. Ultra at $360: unlimited history, order books, 2,000 RPM.
An Enterprise and Bulk Data tier covers full dumps, custom feeds and S3 exports with dedicated support, priced on request.
Venues and data
Polymarket only. The site states it is an independent project not affiliated with, endorsed by or sponsored by Polymarket. Coverage is described as 100% of markets, open and resolved.
Where it falls short
No Kalshi. A cross-venue backtest needs a second data source.
The free tier is a sample, not a research dataset: 10-minute granularity, one month of history, no books. The 1-minute series starts in August 2025, so anything earlier is not available at that resolution.
It is an API, not a chart. Expect to write code or load exports into a notebook.
Who should use it
Traders modelling fills and slippage on Polymarket, and researchers who need a clean archive instead of scraping the CLOB themselves. Casual users who want a price chart should look at a dashboard instead.
Questions about PolymarketData
How much is PolymarketData?
There is a free tier with 10-minute data and a one-month window. Paid plans are Trader at $60 per month, Pro at $120 per month and Ultra at $360 per month. Enterprise bulk data is quoted on request.
Does PolymarketData have Kalshi data?
No. It covers Polymarket only.
Does PolymarketData include order book history?
Yes on paid plans. L2 order book snapshots are included on Trader, Pro and Ultra. The free tier excludes historical order books.
How far back does PolymarketData go?
Minute-level prices, metrics and L2 books run from August 2025 onward. Ultra is the only self-serve plan with unlimited history; Pro is capped at the last 3 months and Trader at the last month.
Trackers find the edge. Calculators size it. Alerts time it.
When it is time to execute, the free Kairos terminal trades Kalshi, Polymarket and Predict.fun from one book.