You’ve done a few token swaps on Uniswap. Maybe you’ve even provided some liquidity. Now you keep hearing people mention “1inch” and “better prices” and “slippage savings.” What are they talking about?
This is the DEX aggregator explained in plain language — what it does, why it often beats going directly to Uniswap, and how to use one without stress. If you haven’t done your first token swap on Uniswap yet, start there. This post picks up where that one left off.
What a DEX Aggregator Actually Does
When you swap tokens on Uniswap, Uniswap only looks at its own liquidity pools. If ETH/USDC liquidity is thin at that moment, or if your trade is large enough to move the price, you might get a worse rate than you’d expect. Uniswap doesn’t check whether Curve or Balancer has better prices. It just uses its own pools.
A DEX aggregator fixes that. It checks prices across dozens of exchanges — Uniswap, Curve, Balancer, SushiSwap, and others — in a single query, then routes your trade through whichever combination gives you the best effective price.
Here’s a concrete example. Say you’re swapping $10,000 worth of ETH to USDC. If you go directly to Uniswap, the whole trade goes through Uniswap’s ETH/USDC pool, and your trade size might push the price slightly against you. An aggregator like 1inch might instead route 40% through Uniswap V3, 35% through Curve, and 25% through Balancer — splitting the trade to reduce that price impact. You pay roughly the same gas as a single Uniswap swap, but you often end up with more USDC at the end.
That gap — the difference between the naive single-DEX price and the aggregated best price — is where the savings live. On small trades it’s negligible. On large trades, it can be real money.
How to Use 1inch: A Step-by-Step Walkthrough
1inch is the most widely used DEX aggregator on Ethereum mainnet and most major Layer 2 networks (Arbitrum, Base, Polygon, and others). It’s audited, battle-tested, and the interface feels almost identical to Uniswap — so if you’ve already done a swap before, you’ll be comfortable here.
Step 1: Go to app.1inch.io
Type the URL directly into your browser. Don’t search Google and click a sponsored result — phishing sites targeting crypto users regularly buy ads for popular DeFi tool names. Bookmark the real URL after your first visit.
Step 2: Connect your wallet
Click “Connect Wallet” and select MetaMask (or whatever software wallet you use). The flow is identical to Uniswap — approve the connection, and you’re in.
Step 3: Select your tokens
Choose what you’re swapping from and what you want to receive. 1inch supports thousands of tokens across Ethereum and L2s. Enter your amount.
Step 4: Check the route before you confirm
Before you approve anything, look for the routing diagram or click “Route.” This shows you which DEXes 1inch is using and in what proportions. This is the aggregator doing its job — and it’s worth glancing at so you understand where your money is going.
Step 5: Compare the price
1inch shows you the price you’d get on 1inch versus what Uniswap V3 would give you directly. If the difference is trivial (common on small trades), you might decide Uniswap is fine for simplicity. If you’re saving 0.3% on a $5,000 trade, that’s $15 in your pocket for doing nothing different.
Step 6: Set slippage, then approve and swap
Review your settings (more on this below), approve the transaction in MetaMask, then confirm the swap. Done.
Key Settings You Need to Understand
The default settings work fine for most swaps, but knowing what they mean helps you catch problems before they cost you.
Slippage tolerance
Slippage is how much price movement you’ll accept between when you submit the transaction and when it executes on-chain. Network congestion, other traders, and market volatility all happen in that window. The default on 1inch is usually 0.5%, which covers most situations. For stablecoin-to-stablecoin swaps, 0.1% is sufficient. For volatile or low-liquidity tokens, you might need 1–2%. Set it too low and your transaction fails. Set it too high and you give the system permission to give you a worse price than expected.
Partial fill
When enabled, this lets your swap execute even if only part of the order can be filled at your target price. For most users, leaving this on is fine — a partial fill at a good price beats a failed transaction.
Fee-on-transfer tokens
Some tokens charge a percentage fee every time they’re transferred between wallets. If you’re swapping one of these and the output looks lower than expected, that’s why. 1inch detects fee-on-transfer tokens automatically and adjusts its price calculations — which is one advantage over going directly to Uniswap, which doesn’t always flag this clearly.
Gas settings
You can choose between standard and fast execution. Unless you have a specific reason to need your transaction confirmed in the next block or two, standard is fine. Paying for fast gas on a non-urgent swap is usually wasted money. Gas costs on L2 networks (Arbitrum, Base) are low enough that this barely matters — but on Ethereum mainnet, it can add up.
When a DEX Aggregator for Beginners Actually Matters (And When It Doesn’t)
Not every swap benefits from routing through an aggregator. Here’s an honest breakdown so you don’t feel like you’re doing something wrong when you skip 1inch:
Use 1inch when:
- You’re swapping $5,000 or more. Price impact on large trades is where aggregators earn their keep. Even a 0.2% improvement is $10 on a $5,000 swap — free money for a 30-second check.
- You’re swapping stablecoins. Curve Finance often has dramatically better rates for stable-to-stable swaps (USDC → USDT, DAI → USDC) than Uniswap. 1inch routes through Curve automatically.
- You’re trading an obscure token. It might have better liquidity on a DEX you’ve never heard of. 1inch indexes hundreds of pools and knows about most of them.
- You’re already comfortable with connecting wallets and approving transactions and want to be smarter about execution.
Uniswap directly is fine when:
- You’re swapping $100–$500. The price difference is usually less than a dollar — not worth switching tools for that.
- You’re trading major pairs like ETH/USDC on Ethereum or a major L2. When one DEX already has deep liquidity, the routing benefit mostly disappears.
- You want simplicity over optimization. There’s nothing wrong with using the tool you know. Optimization is only worth it when it’s worth it.
The honest answer is: for most crypto newcomers doing occasional swaps, the difference is small. For people moving larger amounts regularly, 1inch pays for itself quickly.
Other DEX Aggregators Worth Knowing
1inch is the most popular, but it’s not your only option. These are the others worth understanding:
Paraswap
A strong competitor to 1inch. Also audited, also widely used. Some traders find it gives better prices on specific token pairs. Worth comparing on larger swaps — you can open both, check the quoted price, and pick the better one.
CoW Protocol
Takes a fundamentally different approach. CoW (Coincidence of Wants) batches trades together and tries to match buyers and sellers directly — before touching on-chain liquidity pools. This protects against MEV (Miner Extractable Value), where bots front-run your transaction to profit at your expense. For larger swaps on Ethereum mainnet, CoW Protocol can be meaningfully better than even 1inch.
Jumper.exchange
Useful when you’re not just swapping but also bridging across chains. If you want to go from ETH on Ethereum to USDC on Arbitrum in one transaction, Jumper combines bridge routing and DEX routing in a single interface.
The Takeaway
A DEX aggregator is a tool that makes every token swap smarter. Instead of routing your entire trade through one exchange, it finds the best combination of pools to minimize price impact and maximize what you receive. For small swaps, the difference is usually negligible. For larger trades or stablecoin swaps, it’s often worth the extra two minutes it takes to check.
1inch is where most people start. It’s straightforward, audited, and widely used. If you’ve already done your first few swaps on Uniswap and know how to connect a wallet, you can use 1inch today — the interface is nearly identical. Open both, enter your trade, and compare the quoted outputs. The better number wins.
If you’re thinking about why liquidity depth affects the prices you see on any DEX, our guide to providing liquidity on Uniswap V3 explains how that works under the hood — and why some pools have better prices than others.
Download: Wallet Security — Your Complete Setup Guide
Before you put serious money into DeFi, your wallet security needs to be solid. Download Wallet Security: Your Complete Setup Guide — David’s step-by-step guide to setting up a hardware wallet, securing your seed phrase, and building the security foundation every DeFi user needs before real money goes on-chain.