There are two very different ways to trade one crypto asset for another. On a centralized exchange you open an account, send the company your money and trade on its books, much as you would with a stockbroker. On a decentralized exchange you connect a wallet you control and swap against a pool of tokens held by a smart contract, with no account and no company holding your funds. The choice affects who can lose your coins, what you pay, how much the price can move against you, what identification you need and what happens when something breaks. This comparison works through each difference and prices the same $2,000 purchase on both. The crypto hub covers the wider market.
What is the difference between a CEX and a DEX?
A CEX holds your crypto and matches trades on its own books, while a DEX is code that swaps tokens straight from your wallet.
| Centralized exchange (CEX) | Decentralized exchange (DEX) | |
|---|---|---|
| Who holds the coins | The exchange, in wallets it controls; you hold a claim on its books | You, in your own wallet, until the swap executes |
| Account and identity checks | Required, under US anti-money-laundering rules | None at the protocol level; a wallet is enough |
| How prices are set | An order book of bids and offers from other customers | A formula based on the balance of tokens in a pool |
| Trading costs | Maker or taker fee, the spread, and withdrawal fees to move coins out | Pool fee, network gas, any front-end fee and price impact |
| Dollars in and out | Bank transfers and cards | None directly; dollars must arrive as stablecoins or ETH |
| Which tokens trade | Assets the exchange chooses to list, and can delist | Any token someone creates a pool for, including copies |
| Settlement | Instant on the exchange's books, on chain only when you withdraw | On chain, in the block that includes the trade |
| Main failure modes | Fraud, insolvency, hacks and withdrawal freezes | Contract exploits, malicious approvals, front-running and user error |
| Recourse | Customer support, or a creditor claim if the firm fails | Generally none, since confirmed transactions cannot be reversed |
| Tax forms | Form 1099-DA from US brokers | Generally none for trades from a self-custody wallet |
Most people who use DEXs also use a CEX, because pools trade tokens for tokens: the first dollars usually become crypto through a company. What DeFi is explains the wider system of protocols that DEXs belong to.
Who holds your crypto on a CEX and on a DEX?
A CEX holds the coins and gives you a claim on its books, while on a DEX the coins stay in your wallet until the swap.
An exchange keeps customer coins in wallets it controls, often pooled together, and your balance is an entry in its database. Trades between customers never touch a blockchain; only deposits and withdrawals do. That is why trading is instant and why a forgotten password can be reset. It also means your coins are only as safe as the company's honesty, security and solvency, and FDIC and SIPC protection do not cover them. A separate guide explains whether crypto is safe on an exchange, including what bankrupt exchanges' customers recovered.
On a DEX, nothing leaves your wallet until you sign the swap, and the tokens you buy land back in it in the same transaction. The price of that control is responsibility. A lost seed phrase cannot be reset, and a signature given to the wrong site can empty the wallet. Before a contract can move a token such as USDC, you must approve it, and an unlimited approval stays in force until you revoke it. Custodial vs non-custodial wallets compares the two models in depth, and how to store crypto safely covers protecting the keys.
How do fees compare on a CEX and a DEX?
A CEX charges a trading fee and a spread, plus withdrawal fees, while a DEX charges a pool fee, network gas and sometimes a front-end fee.
Exchange fees depend on whether an order adds liquidity to the book or takes it, on your monthly volume and on the screen you trade from; crypto exchange fees explained breaks down maker, taker, spread and withdrawal charges.
DEX costs come in different pieces:
- Pool fee. Each pool charges a set percentage of every trade, paid to its liquidity providers. Uniswap's version 3 pools use tiers of 0.01%, 0.05%, 0.3% and 1%, with low tiers for closely related pairs and high tiers for volatile ones. Since late December 2025, Uniswap governance has routed part of that fee, on all version 2 pools and selected version 3 pools, to the protocol instead of the providers, but the trader pays the same total.
- Gas. Every swap is an on-chain transaction paid for in the network's token. A typical swap on Ethereum needs about 123,000 gas, which cost a cent or two on November 2, 2026, and the same transaction on a layer 2 network costs a fraction of that; gas fees explained shows how quickly the price per unit can rise.
- Front-end fee. The website or app used to reach the contracts may add its own charge, from nothing to about 1% of the trade, shown in the swap details before you confirm.
- Price impact. A trade moves the pool's price against itself, more in shallow pools, as the next section shows.
What are slippage and price impact?
Price impact is how much your own trade moves a pool's price, while slippage is any further change between the quote and the moment the trade executes.
A pool's formula prices each extra unit a little worse than the last, so the cost of size depends on depth. At 04:46 UTC on November 2, 2026, the Uniswap pool that pairs USDC and ETH at a 0.05% fee quoted a $2,000 purchase about 4 cents worse than the starting price, beyond the $1 fee. A $200,000 purchase from the same pool would have lost about $396, or 0.2%, to price impact. A thinly traded token in a small pool can lose several percent on a modest order.
An order book has the same problem in a different form: a market order fills against the best offers first and then works through worse ones, while a limit order refuses to trade beyond a set price.
Slippage happens on a DEX because a transaction waits in public, often for a few seconds, before a block includes it, and other trades can move the price in the meantime. Swap screens let you set a slippage tolerance, the worst result you accept; if the price moves past it, the transaction fails, and the gas is spent anyway. The waiting period also lets bots front-run large trades. In a sandwich attack, a bot that sees a pending buy buys first, lets the victim's order lift the price and sells straight after, according to ethereum.org's guide to maximal extractable value. The most a sandwich can take is roughly the tolerance: on $2,000 at a 0.5% setting, about $10. A tighter tolerance, a smaller order or sending the transaction through a private route that skips the public queue all reduce the exposure.
What does a $2,000 swap cost on a CEX and a DEX?
On November 2, 2026, $2,000 bought about 0.8645 ETH on a CEX at assumed fees and about 0.8687 ETH through a 0.05% USDC-ETH pool on Ethereum.
Worked example: Buying ETH with $2,000 on November 2, 2026
Prices: ETH at $2,301.19, the price in the DEX pool at 04:46 UTC, used as the mid-market price for both venues, and Ethereum gas at 0.054 gwei, the 24-hour average base fee plus a typical tip that morning. The CEX fees are assumptions; the DEX figures come from an on-chain quote and gas estimates.
CEX, an order-book purchase funded by a free bank transfer:
- Taker fee, assumed at 0.50%: $10.00
- Half the bid-ask spread, assumed at 0.03%: $0.60
- Received: $1,989.40 of ETH at the mid price, or 0.8645 ETH, held by the exchange
- Withdrawing it to a personal wallet would add the exchange's withdrawal fee
DEX, swapping 2,000 USDC from a self-custody wallet:
- Pool fee: 0.05% × $2,000 = $1.00
- Price impact: about $0.04, from the pool's quote of 0.868663 ETH
- Swap gas: about 123,000 gas × 0.054 gwei = 6,642 gwei, about $0.015
- First-time USDC approval: about 56,300 gas, roughly $0.007
- Received: about 0.8687 ETH in the wallet, for a total cost of about $1.06
The DEX came out about $9.50 ahead, but each assumption can narrow or reverse that:
- A lower exchange fee. At a 0.15% taker fee, the CEX cost falls to $3.60.
- Congestion. At the median gas price in the peak block of the October 29, 2026 surge, 254.75 gwei, the swap would have needed about 0.0313 ETH and the approval about 0.0143 ETH, roughly $103 together at that evening's ETH price of about $2,256.
- Slippage and front-running. With a 0.5% tolerance, the swap could have delivered as little as 0.8643 ETH, slightly less than the CEX.
- Getting the USDC. The DEX route assumes stablecoins already sit in the wallet. Buying them, and later turning ETH back into dollars, usually runs through an exchange or other on-ramp with its own fees.
A layer 2 network cuts the gas to a fraction of a cent, but its pools may be shallower, so the quote's price impact is the number to check. How to buy Ethereum covers the purchase itself, and the crypto converter prices ETH in dollars at the current rate.
How do KYC and listing rules differ?
Exchanges serving Americans must verify customers' identities and choose which tokens to list, while DEX contracts accept any wallet and any token with a pool.
FinCEN's 2019 guidance treats businesses that exchange crypto for dollars or for other crypto as money transmitters. They must register with FinCEN, run an anti-money-laundering program that includes verifying customers' identities, keep records and report suspicious activity. That is why an exchange asks for personal details and an identity document before trading, and why it may hold a withdrawal while it reviews an account. The same guidance treats people using crypto for their own purposes as users, not money transmitters. DEX contracts ask for nothing, but sanctions law still applies to the people using them.
Tax reporting follows the same line. US brokers, including exchanges, report sales on Form 1099-DA: Gross proceeds for sales from January 1, 2025; cost basis for covered assets bought from January 1, 2026 in a custodial account. Swaps from a self-custody wallet generally come with no form, yet each one can still be a taxable sale that belongs on your return, and Form 1099-DA explained covers what brokers send.
Listings differ just as sharply. An exchange decides which tokens to offer, can restrict some for US customers and can delist them. On a DEX, anyone can create a pool for any token, including copies that reuse a real project's name and ticker. Check the contract address against the project's own documentation before buying, and remember that whoever supplied a pool can usually withdraw its liquidity at any time. How to research a cryptocurrency sets out the checks, and crypto scams covers fake-token schemes.
What are the biggest risks on a CEX and on a DEX?
On a CEX the main risk is the company failing through fraud, insolvency or a hack; on a DEX it is exploited code or an irreversible mistake.
| Date | Venue | What happened |
|---|---|---|
| November 2022 | FTX, a CEX | Its founder took over $8 billion of customer money, according to the Justice Department, and the exchange went bankrupt |
| February 21, 2025 | Bybit, a CEX | Hackers the FBI linked to North Korea stole about $1.5 billion |
| November 3, 2025 | Balancer V2, a DEX | A rounding flaw in one family of pools was exploited across five networks, for $121.1 million in losses, per Balancer's post-mortem |
| October 29, 2026 | Binance, a CEX | Hackers the FBI linked to North Korea stole more than $6 billion |
When an exchange fails, customers become creditors who wait for a court process. FTX's estate had paid 105% of allowed customer claims, or 120% for convenience claims of $50,000 or less, as of the fifth distribution on July 31, 2026, valued in dollars at November 2022 prices rather than in the coins customers held. A hacked exchange may or may not cover its customers, and any exchange can pause withdrawals.
DEX failures look different:
- Contract exploits. A flaw in pool code can drain liquidity providers, and audits and years of safe running do not rule one out: the Balancer pools hit in 2025 were a legacy design.
- Malicious approvals. Signing an approval on a fake site lets the attacker move the approved token at any time later, so revoke approvals you no longer need.
- Fake tokens and pulled liquidity. A copied ticker or an abandoned pool can leave a buyer holding something unsellable.
- Mistakes in transit. A transfer to the wrong address cannot be reversed, and one sent on the wrong network may need the recipient's help to retrieve; sending crypto to the wrong network covers what can be recovered.
Both carry market risk. Crypto is volatile and can lose most or all of its value whichever venue it is bought on, as ETH's price history shows.
When does a CEX or a DEX make more sense?
A CEX suits moving between dollars and crypto, while a DEX suits swapping tokens that already sit in a self-custody wallet.
- Dollars in or out. Only a CEX, broker or other on-ramp connects to a bank account.
- Not wanting to manage keys. A CEX offers password resets and support, at the cost of trusting the company.
- Keeping custody. A DEX lets coins stay in your own wallet between trades, so no company can freeze or lose them.
- Tokens a CEX does not list. A DEX may be the only venue, which raises the research burden rather than lowering it.
- Large or urgent trades. Compare the CEX's fee and order-book depth with the DEX's price impact and the network's gas before choosing.
Many people use both: buy on an exchange, withdraw to a wallet they control and swap on chain when they need another token.