A DEX aggregator searches many decentralized exchanges for one swap and routes, or splits, the order along the best path
Liquidity for the same pair is spread across many DEXs and networks, and each pool prices from its own reserves (1inch). A DEX aggregator compares those prices, routes the order along the best path and can split it across several pools to reduce price impact. Many also tap professional market makers who quote privately, not only public pools.
A service that compares swap prices across many decentralized exchanges at once and routes the order along the best path, splitting it across venues when that pays (1inch). 0x compares its API to a flight-comparison site.
How does an automated market maker set the price?
Most DEXs are automated market makers. Instead of an order book, a pool holds two tokens, and each trade shifts their relative price.
x × y = k
- x and y are the pool's two token reserves.
- Their product k stays constant through a trade (Uniswap v1 and v2).
- Buying one token makes it scarcer in the pool, so its price rises.
Liquidity providers
- Anyone can deposit a token pair into a pool.
- LPs take on price risk and earn trading fees.
- Impermanent loss is the main cost of providing liquidity.
Uniswap v3 added concentrated liquidity: LPs place liquidity within a price range.
Uniswap's own example shows why: in v2, a DAI/USDC pool used about 0.50% of its capital in the $0.99 to $1.01 range where nearly all trading happens.
Why does a large trade get a worse price on a DEX?
Price impact grows with trade size relative to pool depth. That is the problem aggregators solve by splitting.
- 9.1%below spot for a 100 ETH swap through one pool, in 1inch's worked example1inch.com
- 3.2%below spot for the same swap split across three pools1inch.com
- 5 to 20 bpsby which Jupiter says RFQ market makers often beat on-chain routing on major pairsdev.jup.ag
How do DEX aggregators route and split orders?
- Scan
Query pools on many DEXs, plus private quotes from market makers where available.
- Price each path
Weigh pool depth, fee tiers and the gas cost of each extra venue.
- Split if it pays
Spread the order across pools only when the better price beats the extra gas.
- Execute
Send one transaction that runs every leg, or hand the order to solvers.
Classic routing vs intents
Classic routing
- You sign a transaction with a route the aggregator found.
- It goes through the public mempool like any swap.
- Examples: 1inch classic, 0x, Jupiter's Metis engine on Solana.
Intents and solvers
- You sign an off-chain intent, what you want, not how.
- Solvers compete to fill it.
- Examples: CoW Protocol batch auctions, Velora Delta, 1inch intent mode.
CoW Protocol says its uniform clearing prices make transaction order irrelevant, which undermines MEV bots, and Velora says its Delta intents avoid public mempool exposure. More on that risk in MEV and sandwich attacks.
An aggregator always splits the order.
Routing splits only when the better price beats the gas of each extra venue (1inch).
Aggregators only use public pools.
Many also use professional market makers who quote privately, RFQ-style (1inch, 0x).
Aggregators work only on one chain.
0x's Cross Chain API queries several bridge providers and returns the best routes across chains.
How is an instant swap aggregator different?
A DEX aggregator works on-chain: you connect a wallet, sign, and pay gas. An instant swap aggregator works between your wallets: you send a deposit and receive the other asset.
SimpleSwap compares quotes from 20+ centralized and decentralized providers for each order and routes it through whichever can execute at that moment.
ChangeNOW is a direct instant exchange that names 15+ CEX and DEX sources in its asset-listing materials. More in CEX vs DEX vs instant swaps.
Questions
What is a DEX aggregator and how does it work?
It compares prices across many DEXs, routes your order along the best path and can split it across pools.
Some also use private quotes from market makers or let solvers compete to fill your order.
Is a DEX aggregator better than using Uniswap directly?
For small trades in deep pools, the difference can be small.
For larger trades, splitting across pools can reduce price impact, as in 1inch's example of 9.1% versus 3.2% below spot.
How do DEX aggregators split orders?
They price each possible path, including pool depth, fee tier and gas, and split the order across several pools only when the better price beats the extra gas.
What does x*y=k mean?
It is the constant product formula: the product of a pool's two token reserves stays constant through a trade, so buying one token makes it more expensive.
What is impermanent loss?
The opportunity cost liquidity providers face when prices change, compared with simply holding the two tokens.
Do DEX aggregators protect against MEV and sandwich attacks?
Some intent-based designs aim to. CoW Protocol uses batch auctions with uniform prices, and Velora Delta avoids the public mempool.
Classic routed swaps go through the public mempool.