Trade with CoW Swap (Coincidence of Wants)

How to use CoW Swap: gasless swaps, MEV protection via batch auctions, and limit orders.

What you'll need (prerequisites)

• Self-custodial wallet (MetaMask, Rabby, etc.)
• ETH or native gas token
• Tokens to gasless swap with
• Familiarity with transaction approvals

Step-by-step

1. Step 1: Connect a self-custodial wallet

   Open CoW Swap's official site (verify the URL — phishing fakes are common). Click "Connect Wallet" and choose your wallet (MetaMask, Rabby, WalletConnect, hardware). Approve the signature request — this does not move funds.

2. Step 2: Select the correct network

   Confirm your wallet is on the network CoW Swap expects (Ethereum mainnet, Arbitrum, Base, Polygon etc.). Wrong-network connections are the #1 source of UX confusion.

3. Step 3: Acquire the input tokens

   CoW Swap swaps themselves are gasless — the trading fee is deducted from your sell token — but the one-time ERC-20 approval still needs a little ETH (or the chain's native token) for gas. Hold a small buffer (~$10-20) for that approval.

4. Step 4: Approve token spend

   For ERC-20 tokens, the first interaction requires an "approve" transaction granting CoW Swap permission to move that token. Approve the exact amount (not unlimited) when possible to limit downside if CoW Swap is ever exploited.

5. Step 5: Execute the gasless swap transaction

   Enter the amount, review the slippage tolerance (0.1-0.5% for stablecoins, 0.5-1% for blue chips, more for thin-liquidity tokens). Click confirm and sign the order in your wallet — a gasless off-chain signature, not an on-chain transaction you submit yourself. A solver then settles your order on-chain; wait for that confirmation.

6. Step 6: Verify on-chain

   Open the transaction on Etherscan / Arbiscan / Basescan. Confirm the balance change matches expectations. Save the transaction hash for tax records.

Common errors and fixes

• Transaction reverted. Most reverts are slippage exceeded, allowance not set, or insufficient gas. Increase slippage marginally and retry, or check Tenderly for the revert reason.
• Stuck pending transaction. Speed up with a higher gas price (replace-by-fee) or cancel by sending a 0-value tx to yourself with the same nonce and higher gas.
• Approved a malicious contract. Immediately revoke at revoke.cash. Move remaining tokens to a fresh wallet if you suspect ongoing compromise.
• Wrong network. Switch chains in your wallet. If funds were sent cross-chain to a contract that doesn't exist on the destination, contact the bridge support.
• Slippage too high. For thin-liquidity tokens, split the swap into smaller chunks or route via an aggregator (1inch, CoW Swap, Matcha) which finds better paths.

FAQ