Quick answer
A DEX aggregator like 1inch or Jupiter automatically finds the best token swap price by routing your trade across multiple DEX pools simultaneously. To use one: connect your wallet to the aggregator's website, select your input and output tokens, enter the amount, review the quoted price and route, approve the token if required, and confirm the swap. Aggregators typically save 0.1-2% compared to single-DEX trading, especially for large swaps.
Why use a DEX aggregator?
When you trade directly on a single DEX like Uniswap, you're limited to that protocol's available liquidity. If Uniswap's ETH/DAI pool is thin, you'll face high slippage. An aggregator like 1inch queries dozens of DEXes simultaneously — Uniswap, Curve, Balancer, SushiSwap, and more — and finds the optimal route, sometimes splitting your trade across multiple sources for a better overall price.
For small trades (under $1,000) on major pairs, the price difference is often negligible. For larger trades ($10,000+) or for trading less liquid tokens, aggregators can save meaningful amounts — sometimes 0.5-2% or more on the execution price.
Step-by-step: Using 1inch on Ethereum/L2
- 01
Go to 1inch.io
Navigate to app.1inch.io in your browser. 1inch supports Ethereum, Arbitrum, Optimism, Base, BNB Chain, Polygon, Avalanche, and more. Select your network from the dropdown.
- 02
Connect your wallet
Click 'Connect wallet' and select your wallet. Approve the connection. 1inch requires read-only access to your address — it cannot move funds without your signature.
- 03
Select tokens
In the 'From' field, choose the token you want to sell. In the 'To' field, choose the token you want to receive. Search by name or paste the contract address for less common tokens.
- 04
Enter amount and review quote
Enter the amount you want to swap. 1inch will show you the best available rate, estimated price impact, and the routing path (which DEXes and pools your trade will pass through). Click 'Route details' to see the full breakdown.
- 05
Check slippage settings
Click the settings icon to adjust slippage tolerance. 1inch's default is typically 0.5-1% — appropriate for most trades. Lower it for stable pairs (0.1%), raise it slightly for illiquid tokens.
- 06
Approve token (if needed)
For tokens other than ETH/native gas, you must first approve 1inch's router contract to spend your tokens. This is a one-time approval per token. Click 'Approve [Token Name]' and confirm in your wallet.
- 07
Confirm the swap
Click 'Swap' and review the final transaction details in your wallet popup. Check the 'Minimum received' figure — this is the worst-case amount you'll get given your slippage tolerance. Confirm to execute.
Best aggregators by blockchain
Different aggregators dominate on different chains:
| Aggregator | Best chains | Standout feature |
|---|---|---|
| 1inch | Ethereum, Arbitrum, Base, BSC, Optimism | Deepest route optimisation, MEV protection via Fusion |
| Paraswap | Ethereum, Polygon, Avalanche, BNB Chain | Strong on Ethereum; used by Ledger Live |
| Jupiter | Solana | The dominant Solana aggregator; best SOL token routing |
| Odos | Multi-chain EVM | Multi-input/output swaps; excellent for portfolio rebalancing |
| CoW Protocol | Ethereum, Gnosis Chain | Off-chain order matching; strong MEV protection |
1inch Fusion — MEV-protected swaps
1inch Fusion is a mode that routes your swap through off-chain 'resolvers' (professional traders who compete to fill your order at the best price) rather than submitting directly to the on-chain mempool. This provides strong MEV protection — your transaction isn't visible to sandwich bots — and often achieves better pricing than standard on-chain swaps.
The tradeoff is that Fusion swaps may take slightly longer to execute (seconds to minutes depending on liquidity) and are not available for all token pairs. For large ETH/USDC swaps, Fusion is often the best option available.
Frequently asked questions
Is using a DEX aggregator safe?
The major established aggregators (1inch, Paraswap, Jupiter) are generally considered safe — they don't hold your funds, and their smart contracts are well-audited. The main risk is interacting with a phishing site impersonating a legitimate aggregator. Always verify the URL, bookmark official sites, and never enter your seed phrase on any aggregator website.
Do aggregators charge fees?
Most aggregators are free to use — they generate revenue by taking a small portion of the price improvement they find (effectively they share in some of the savings they generate). 1inch charges no additional fee on top of the underlying DEX fees. Some aggregators do charge a small protocol fee (0.1-0.3%) on certain token pairs — always check the fee breakdown shown before confirming.
When should I use an aggregator vs a direct DEX?
For swaps over $1,000, always use an aggregator — the potential price improvement justifies it. For small swaps of major pairs (under $500), a direct Uniswap or Curve swap is fine. For illiquid or exotic tokens, aggregators are especially valuable as they can find liquidity across many sources. For Solana, Jupiter is essentially the only good option for all swaps.
What is the difference between a DEX aggregator and a DEX?
A DEX (like Uniswap) holds liquidity in its own smart contracts and executes trades directly against those pools. An aggregator (like 1inch) does not hold its own liquidity — it is a routing layer that queries other DEXes and finds you the best execution across multiple sources. The aggregator routes your trade to the DEX(es) with the best price.
Can aggregators help with gas fees?
Aggregators can sometimes reduce total gas costs by batching multiple hops into a single optimised transaction, and by routing through cheaper protocols. 1inch Fusion mode eliminates gas entirely for the swap (gas is paid by the resolver). However, the underlying blockchain gas fee environment is the dominant factor — use L2 aggregators (1inch on Arbitrum, Jupiter on Solana) for truly low-cost swaps.