A neutral list of tools people use for Kalshi and Polymarket arbitrage, written by one of them. Last checked 4 November 2026.
We build Arbitrage Agent, so read this with that in mind. To keep it fair, every statement about another tool below is what that tool says about itself on its own website, with the link so you can check it. We do not rank them, and prices and features change, so always confirm on the vendor's page before you pay.
Arbitrage Agent
Signal feed with step-by-step guides
Matches markets across Kalshi and Polymarket, checks their resolution rules, and lists the pairs whose combined cost clears fees. The Starter plan ($29/month) is signals only: you place both orders yourself, on your own accounts, following a guide. Alerts and automated execution are planned for the Operator plan, which is coming soon. Net edges are typically small (the median is below 1% per position), and resolution differences between two markets are a real risk.
According to its FAQ it has no monthly fee and takes a small percentage of each successful arbitrage trade; the percentage was not published there when we last read it.
Its site did not load for us on the day we checked, so treat this entry as the last thing we read rather than today's state.
Do you want software to place orders for you? Of the tools above, Claw Arbs describes order execution today. Arbitrage Agent Starter does not place orders; automated execution is planned for Operator.
Which venues do you trade on? The tools differ: some cover only Polymarket, others several prediction markets and sportsbooks. Check the venue list for the ones you can legally and practically use.
How do you want to pay? A flat monthly price, a share of each trade, and free DIY code with your own time are different trade-offs.
Whatever you pick, read both markets' resolution rules and the platforms' current fee schedules yourself. No tool removes resolution risk, and none can promise a profit.