1inch - The Aggregation King
1inch Network processes over $400B in cumulative volume by scanning 400+ liquidity sources to find the mathematically optimal route for every swap. Its Pathfinder algorithm does in milliseconds what would take a human hours - evaluating thousands of possible paths and picking the one that maximizes your output.
Pathfinder v2 - How It Finds the Optimal Route
Pathfinder is 1inch's proprietary routing algorithm. It models the entire DeFi liquidity landscape as a weighted directed graph where nodes are tokens and edges are liquidity pools. Edge weights encode gas cost, fee tier, and price impact - then it finds the minimum-cost path.
Every pool across all supported DEXs becomes a node. Edge weights encode fee tier, current reserves, and estimated gas cost per hop.
Pathfinder evaluates direct swaps, 2-hop routes (TOKEN->ETH->USDC), 3-hop routes, and multi-split paths where trade value is divided across several pools simultaneously.
Each hop costs extra gas (~15-50k per step). Pathfinder only splits routes when price improvement exceeds incremental gas cost.
Returns calldata bundle - one transaction, multiple DEX interactions, atomic execution. If any hop fails, entire trade reverts.
Fusion Mode - Gasless Swaps via Dutch Auction
Fusion mode is 1inch's most distinctive feature: swap tokens without spending any ETH on gas. Instead of broadcasting a transaction, you sign an off-chain EIP-712 intent and professional resolvers compete to fill it.
Off-chain EIP-712 signature: "Swap 1 ETH for at least 3,250 USDC, expires in 60 seconds." Zero gas from you.
Starting price above market rate. The offered rate decays over 60-120 seconds, making it increasingly profitable for resolvers to fill.
Registered resolver pays gas and executes the swap when their profit margin covers costs. They earn the spread.
Tokens arrive. You paid zero ETH gas. MEV bots can't front-run because order is private to whitelisted resolvers.
Chi Gas Saver - 20-40% Gas Reduction
Chi is 1inch's gas-saving token mechanism. Users mint Chi tokens by burning gas credits during swaps, reducing effective gas costs significantly. While Fusion mode is now the preferred approach, Chi remains available for direct swaps.
1inch Limit Orders - Trade at Your Price
Unlike standard market orders that execute at whatever the market price is, limit orders on 1inch let you specify the exact price at which you want to trade. The order persists until the market crosses your threshold, then Pathfinder executes it at the best available route.
"I want to sell ETH at $3,400 or better" - below the market price you specify a minimum acceptable rate.
Off-chain EIP-712 signature. Order persists in the protocol - not on-chain until filled. No gas consumed while waiting.
When price crosses your threshold, Pathfinder finds the optimal route to fill your order across the best available liquidity.
Order executes on-chain. You get the tokens at your specified price or better. Gas paid from your order value.
Executes immediately at whatever the market price is - no control, no price guarantee.
Executes only when price meets your threshold. Better rate, MEV protection via Pathfinder routing, no upfront gas.
When Does 1inch Actually Help? (vs Direct DEX)
1inch adds meaningful value for large trades and exotic pairs, but for small swaps on major pairs, a direct Uniswap transaction is often simpler, cheaper, and equally good.
| Scenario | 1inch Advantage | Verdict |
|---|---|---|
| Swap $500 ETH -> USDC | ~0.1% better price, +$10-20 extra gas | Direct is fine |
| Swap $50,000 ETH -> USDC | Splits across 3-4 pools, saves $200-400 | Use 1inch |
| Swap $500,000 WBTC -> DAI | 5-8 routes, saves $3,000-8,000+ | Use 1inch |
| Swap ETH -> obscure altcoin | Finds all pools including Curve + Balancer | Use 1inch |
| Stablecoin swap (USDC -> USDT) | May route via Curve, minimal diff | Either works |
| Gasless swap needed (no ETH in wallet) | Fusion mode - $0 gas to user | Use 1inch Fusion |
| Set-it-and-forget limit order | Native limit order protocol with Pathfinder fills | Use 1inch |
Gas Cost vs. Savings - The Breakeven Calculator
Each additional route improves your price but costs extra gas. Pathfinder only adds routes when savings outweigh the cost. Drag the sliders to see where the breakeven is for your situation.
Explore the Broader Ecosystem
Frequently Asked Questions
What makes 1inch's routing different from other aggregators?
1inch's Pathfinder algorithm is a graph traversal engine that models all DeFi liquidity as a weighted directed graph. It evaluates direct swaps, multi-hop routes (up to 6 hops), and split routes simultaneously, then picks the combination that maximizes output tokens after gas costs. It covers 400+ sources across 12+ chains, giving it the widest reach of any aggregator.
How does 1inch Fusion mode work and is it safe?
Fusion mode replaces standard on-chain swaps with off-chain Dutch auctions. You sign an EIP-712 intent ('swap X for at least Y at price P, expires in 60s') - zero gas. Resolvers compete to fill your order, paying gas themselves in exchange for the spread. It's safe as long as you use the official 1inch contracts, and it provides excellent MEV protection since the order never touches the public mempool.
What is the Chi gas saver and should I use it?
Chi Gas Saver is an 1inch innovation where users mint Chi tokens by burning gas tokens during swaps. The gas savings are typically 20-40% compared to a standard transaction. The main risk is smart contract risk from the Chi token contract, which has been audited but carries non-zero risk. Most users simply use Fusion mode for gasless execution instead.
How much can 1inch save on a large trade?
For a $100,000 ETH -> USDC swap, 1inch typically saves $200-500 versus a single Uniswap V3 transaction, thanks to multi-pool routing that avoids concentrated price impact on any single venue. The savings scale with trade size: a $1M trade could see $2,000-10,000+ in improvement. Breakeven is around $5,000-10,000 on Ethereum mainnet; on L2s it's much lower.
Does 1inch support limit orders?
Yes. 1inch has a native limit order protocol that lets you place orders at specific prices. Unlike traditional limit orders that sit in an order book, 1inch's limit orders are filled by the Pathfinder algorithm - if the price crosses your threshold, the order executes automatically at the best available routing. There's no explicit order expiration - orders persist until filled or cancelled.
Which chains does 1inch support?
1inch supports 12+ chains: Ethereum, BNB Chain, Polygon, Arbitrum, Optimism, Avalanche, Fantom, Gnosis, zkSync Era, Base, Linea, and Aurora. Fusion mode is primarily on Ethereum with expansion to L2s in progress.