On this page (7 sections)
Who should skip this?
Skip CoW Swap if you need a fill in the next few seconds, you are swapping on Solana, or you have never signed an Ethereum transaction. CoW is an intent auction, not a Uniswap pool. Patience is part of the product.
- You need an immediate on-chain fill (arbitrage, liquidation, block-time trading)
- You are a Solana-only user — CoW's main flow is Ethereum (and selected EVM chains)
- You will not read the order expiry and you will assume a signed intent is a fill
Should you use CoW Swap?
Yes, on Ethereum, when the cost of being sandwiched or getting a mediocre Uniswap fill matters more than settling in the next block. CoW Swap uses signed intents; solvers compete to fill you, often with coincidence of wants (two orders matching each other) or routed on-chain liquidity.
No, when speed is the product: liquidations, MEV-sensitive arb, or a UI that must confirm before you walk away from the keyboard. Uniswap (or another AMM) is the honest tool for instant inclusion. CoW vs 1inch is a separate comparison if you are choosing aggregators.
What is CoW Swap and how does it work?
You sign an EIP-712 order stating what you sell, what you buy, and your limit. That signature is not yet a blockchain transaction. Solvers bid to settle a batch. If they find a better price than your limit, the surplus is shared: CoW's protocol fees take up to half of any improvement over the quote (or over your limit, for out-of-market limit orders), capped at 0.98% of volume, plus a volume fee of 2 bps on most pairs; the rest returns to you. If they cannot fill before expiry, the order dies and you pay no swap gas.
Because the order is not sitting as a public-mempool AMM swap with a fat slippage tolerance, classic sandwiching of your Uniswap trade is not the failure mode. You still face solver, protocol and token risk. Official app: swap.cow.fi (checked August 2026).
| CoW Swap | Uniswap | 1inch | |
|---|---|---|---|
| Mechanism | Signed intent + batch solvers | On-chain AMM pool | Aggregator router |
| MEV on your swap | Structurally reduced | High if slippage is wide | Depends on routing |
| Speed | Batch — not next-block guaranteed | Next block if it lands | Next block if it lands |
| Gas if unfilled | Usually none for the swap | You already sent a tx | You already sent a tx |
How do you place a first CoW order?
Treat the signature as a live limit order, not as a completed swap. Set a sensible expiry. If it does not fill, you still have the tokens — do not 'retry' on a phishing domain.
- 01
Open swap.cow.fi
Connect an Ethereum wallet. Confirm you are on the intended chain in the UI.
- 02
Pick tokens and a limit
Enter sell and buy assets. Read the quoted price and slippage/limit. A market-like order still has a limit underneath.
- 03
Sign the intent
This is EIP-712, not necessarily an on-chain swap yet. Read the wallet prompt. You are authorising solvers to settle within those bounds.
- 04
Wait for settlement or expiry
Filled orders deliver tokens to the same wallet. Expired orders cost you the signature, not a failed AMM swap's gas, in the usual flow.
Surplus is extra output versus your limit when solvers do better. It is not a yield product. Do not size a trade because you hope for surplus.
The verdict: should you swap with CoW?
Yes, for Ethereum spot size where a sandwich or a lazy Uniswap route would cost more than waiting a batch. No, for urgency, for Solana, or for anyone who will confuse a signature with a fill.
If CoW does not fill, Uniswap is still there. If you are choosing routing brands, read CoW vs 1inch. If you have not swapped on Ethereum at all, learn a simple Uniswap swap first so you recognise what CoW is protecting you from.
Sources
Primary documentation and data this guide relies on. Links checked .
- Fair Combinatorial Batch Auction — CoW Protocol documentation. Signed intents collected off-chain and auctioned to competing solvers in batches
- Coincidence of Wants — CoW Protocol documentation. CoWs: two orders matched directly against each other
- Signing schemes — CoW Protocol documentation. Orders are EIP-712 signed messages, not immediate on-chain transactions
- MEV protection — CoW Protocol documentation. CoW Protocol's intent/batch design protects orders from sandwich MEV
- Fees — CoW Protocol documentation. Surplus/price improvement mechanics and protocol fees on CoW Swap orders
- Core contracts — CoW Protocol documentation. Networks where CoW Protocol/CoW Swap is deployed
Frequently asked questions
CoW Swap vs Uniswap?
Uniswap executes against a pool as soon as the transaction is included. CoW batches signed intents with solver competition and stronger sandwich resistance. Use Uniswap for speed; CoW for Ethereum trades where execution quality matters more than the next block.
What is surplus?
If solvers settle you better than your limit, extra tokens are returned as surplus after CoW's protocol fees (up to half of the improvement, capped at 0.98% of volume, plus a small volume fee). It is not guaranteed and it is not APY.
Do I pay gas to place a CoW order?
Signing the intent is usually off-chain. Exceptions: selling native ETH (CoW's Eth-flow) and a first-time token approval need an on-chain transaction that costs gas. Otherwise, gas is paid when a solver settles the batch on-chain. Unfilled expired orders typically do not cost swap gas — read the current UI, because gas policy can differ by chain.
Is CoW only on Ethereum?
The flagship flow is Ethereum, but CoW Protocol also runs on several L2s and EVM chains, including Arbitrum, Base and Gnosis Chain (September 2026) — check swap.cow.fi for the network list rather than assuming every L2 is supported.