CEX vs DEX: centralized vs decentralized crypto exchanges

Almost every crypto journey starts on an exchange — but "exchange" covers two very different things. A centralized exchange (CEX) is a company that runs a trading platform and holds customers' funds, much like a broker. A decentralized exchange (DEX) is software running on a blockchain that lets people swap tokens directly from their own wallets, with no company holding the money in between. This guide explains how each works, what you give up and gain, and how to choose.

How a centralized exchange works

When you sign up to a CEX, you create an account, verify your identity and deposit money by bank transfer or card. The exchange keeps your coins in its own wallets and records your balance in an internal database. When you buy, your order is matched against other customers' orders in the exchange's order book; the coins usually do not move on the blockchain until you withdraw them.

That design makes centralized exchanges fast and familiar: you get customer support, password resets, fiat on- and off-ramps and often extras such as staking or recurring buys. The trade-off is custody — until you withdraw, the exchange controls the private keys. The collapses of Mt. Gox in 2014 and FTX in 2022 showed what can happen when a platform loses or misuses customer funds. Most regulated exchanges must also run KYC (know-your-customer) checks and can freeze accounts under court orders or their own rules.

If you are buying for the first time, our step-by-step guide on how to buy bitcoin walks through a typical CEX purchase.

How a decentralized exchange works

A DEX is a set of smart contracts — programs deployed on a blockchain such as Ethereum, Solana or a layer-2 network. You connect a self-custody wallet, approve the contract to use a specific token and sign a transaction. The swap settles on-chain, and the new tokens land straight in your wallet.

Most popular DEXs use an automated market maker (AMM): instead of matching buyers and sellers, they hold pools of two tokens supplied by liquidity providers, and a formula sets the price based on the pool's balance. Others, such as Hyperliquid, run a full on-chain order book. Because anyone can create a pool, DEXs often list new tokens long before centralized platforms — which is both their appeal and a major source of risk.

There is usually no account and no identity check at the protocol level, though some website front-ends block certain countries. You pay the blockchain's network fee (gas) on top of the trading fee, and large trades in thin pools can suffer slippage, meaning you get a worse price than quoted. To learn the wider landscape, start with what DeFi is.

Side-by-side comparison

Pros and cons of centralized exchanges

Pros and cons of decentralized exchanges

Fees and costs in practice

On a centralized exchange you typically pay a trading fee (often lower for "maker" orders and higher volumes) or a spread built into "instant buy" prices, plus fees for card deposits and crypto withdrawals. Instant-buy buttons are convenient but usually cost more than placing an order on the exchange's trading screen.

On a DEX the total cost is the pool or protocol fee, the network fee and any slippage. On busy networks a simple swap can cost more in gas than the trade is worth, while on low-fee chains and layer-2 networks it can cost cents. Always look at the "minimum received" figure before confirming.

Security: different risks, not zero risk

Neither option is "safe" by default. With a CEX the main risks are counterparty risks: hacks of the exchange's hot wallets, mismanagement, insolvency or account restrictions. Choosing licensed platforms, enabling app-based two-factor authentication and not leaving large balances on the exchange all reduce that risk.

With a DEX the risk shifts to you and the code: a lost recovery phrase, a phishing site, a buggy contract or a malicious token. A hardware wallet keeps your keys offline even when you connect to DeFi apps, and our guide on how to store crypto safely explains how to protect your seed phrase.

Which should you use?

Many people use both. A common pattern is to buy with bank money on a reputable centralized exchange, withdraw to a personal wallet, and use a DEX only when they need a token or feature that centralized platforms don't offer. If you only want exposure to major coins and value support and simplicity, a well-regulated CEX may be all you need. If you value self-custody and on-chain access and are willing to learn how wallets, gas and approvals work, a DEX gives you more control — along with more responsibility.