How does a crypto swap work?
Most swaps run against liquidity pools. A pool is a smart contract holding reserves of both tokens in a pair, funded by people who earn a share of its swap fees. When you swap, the contract takes in the token you pay with, sends back the token you asked for and moves its price along a public formula. Nobody has to be on the other side of your trade at that exact moment, because the pool always is.
A concrete example helps. Say you swap 1 ETH for USDC. The pool takes in your ETH, prices it from the ratio of its reserves, keeps its swap fee, often a fraction of a percent, and sends the USDC to your address, all inside one transaction. If the numbers cannot meet the terms you signed, nothing happens at all.
That is the biggest break from a centralized exchange, where a matching engine pairs your order with another customer's and the company keeps the books. On-chain, the rules are code anyone can read, and every fill is recorded publicly on the blockchain. No permission, account or minimum balance is required to use it.
Liquidity pools are the building block of decentralized exchanges, and they are worth a few minutes of study before your first swap. The practical takeaway is simple: deeper pools move less when you trade, so a pair's liquidity decides how good your rate can be.
What happens when you confirm a swap?
A swap is one transaction with a strict sequence inside it, and your wallet shows you the exact terms before anything moves.
- You sign a transaction that names the tokens, the amount you pay and the minimum you accept in return.
- The network includes it in a block. The swap contract pulls in the token you pay with, runs its pricing formula and sends the destination token to your address.
- If any condition fails, for example the price moved past your tolerance, the whole transaction reverts and your tokens never leave the wallet.
This all-or-nothing settlement is what makes a swap safe to attempt, because there is no state where you have paid and not received. The same idea stretched across two blockchains powers atomic swaps, the mechanism behind trustless cross-chain trades.
How is swapping different from buying crypto?
Buying crypto means paying with dollars, euros or another government currency, usually through an exchange or a card on-ramp. Swapping starts and ends in crypto: you already hold one token and trade it for another, on-chain, from your own wallet. The two actions feel similar inside an app, but they settle in very different places.
- Starting point
- A purchase starts from cash in a bank account. A swap starts from a token already in your wallet.
- Where it settles
- A purchase settles on the provider's private ledger. A swap settles on the blockchain in one transaction.
- Custody
- A purchase sits with the provider until you withdraw. A swap moves tokens wallet to wallet, and only when the trade fills.
- Typical costs
- A purchase carries card or service fees set by the provider. A swap costs the network fee plus the rate you accept.
What does a swap cost?
Two numbers decide the cost: the network fee and the rate. The network fee pays the validators who confirm your transaction, and it is the same whether you swap $50 or $50,000. A typical swap on Ethereum mainnet consumes about 180,000 gas, which came to roughly $0.21 at the mid-2026 average gas price, according to ethereum.org. On layer 2 networks the same swap usually costs a few cents.
The rate decides how much you actually receive, and it differs venue to venue because liquidity is spread across thousands of pools. Checking them one by one is impractical, so aggregation does it in a single query. The result on 1inch is competitive rates, aggregated across 300+ sources. Before you confirm, two settings deserve a look: slippage tolerance, which caps how far the rate can move while your transaction waits, and the network fee itself, covered in the gas fees guide.
How much crypto is swapped on-chain?
On-chain swapping grew from a niche into a mainstream market within two years, and the numbers are public, so you can check them yourself.
The volume figures come from CoinGecko's 2026 exchange activity report, which also recorded the DEX share peaking at 24.5% in June 2025. The ownership estimate comes from Crypto.com's market sizing research. Live volume for every major venue is tracked openly on DefiLlama.
It took time to get here. The pool model dates back to 2017, when the earliest automated market makers went live, and for years on-chain swaps stayed a specialist tool with painful fees. Cheap layer 2 blockspace, better wallets and aggregation turned them into an everyday way to trade, and the volume shift shows it.
The reasons people swap are practical: to move from a volatile token into a stablecoin, to enter a new asset without cashing out first or to rebalance a portfolio without giving up self-custody. Each of those is a token-for-token trade, which is exactly what a swap is.
Do you keep control of your tokens during a swap?
On 1inch, yes. Swaps are non-custodial. You sign each transaction from a wallet you control, tokens leave it only in the moment a swap settles and there is no deposit step at any point. 1inch routes the swap across on-chain liquidity sources and never takes custody of your assets.
Custody is also the sharpest dividing line between venues. DEX vs CEX compares the two models dimension by dimension, and when you are ready to try a swap, how to swap crypto turns the theory into practice step by step. Every guide in this series lives on the Learn hub.
Common questions about crypto swaps
Nothing fundamental. A swap is a trade that settles on-chain in a single transaction, wallet to wallet. People tend to say 'trade' on venues with order books and 'swap' for exchanges that run through a smart contract.
Almost. A route needs liquidity somewhere between the two tokens, and routers can chain several pools together, so even pairs with no direct pool usually fill. Very new or very small tokens sometimes lack real liquidity, and then no venue can quote a fair rate for them.
For a standard swap, yes, because the transaction runs on one chain. If your tokens live on different networks, a cross-chain swap combines the bridge and the swap into a single flow, so you do not have to move assets across by hand.
There is no protocol minimum. The practical floor is the network fee. A $5 swap that pays $0.20 in gas gives up 4% before the rate is even considered, while the same swap on a low-fee network barely notices the cost.
See a live quote
Pick a pair and watch the route build. Connecting a wallet is free, and nothing moves until you sign.
