A Complete Guide to the 1inch Swap

Introduction to 1inch Swap

1inch is a leading DeFi aggregator that aims to make crypto trading more efficient and user-friendly. Its Swap product combines liquidity from many sources to get you the best token prices and offers multiple ways to trade, including across different blockchains. This comprehensive guide breaks down all three swap modes on 1inch — Simple, Advanced, and Limit Order — and shows how Fusion and Fusion+ enable gas-free swaps and cross-chain trades.

The platform has established itself as a sophisticated trading infrastructure that goes beyond basic token swapping. By aggregating liquidity from over 100 sources and implementing advanced execution mechanisms, 1inch Swap provides traders with competitive rates while maintaining high security standards. You will also learn about 1inch's security stack and why it positions itself as a step up from conventional aggregators and DEX platforms.

Swap Modes on 1inch: Simple vs. Advanced vs. Limit Orders

1inch provides a flexible trading interface with three modes to suit different user needs: Simple mode, Advanced mode, and Limit Orders. All modes use 1inch's aggregation technologies to secure competitive rates but offer different features and levels of control. This multi-mode approach allows both beginners and experienced traders to find the right balance between simplicity and customization.

Simple Mode

This mode is designed for quick, straightforward token swaps with minimal complexity. The interface is clean and easy to use — it focuses primarily on swapping one token for another without extra charts or settings. Simple mode represents the most streamlined path to executing trades, making it ideal for users who prioritize speed and convenience over detailed control.

Under the hood, Simple mode uses 1inch's Fusion mechanism and Fusion+ for cross-chain swaps. No gas fees appear because resolvers cover gas costs and protect transactions from front-running. This resolver-based execution model fundamentally changes how users interact with DeFi protocols, removing the traditional friction of managing gas fees across different networks.

Fusion+ stands out because it lets you swap across chains without any bridges, all from one page, so you keep custody of funds and avoid bridge risks. You don't need to pay network fees or hold ETH or BNB for gas, as the swap is executed via resolvers who cover gas costs. This gasless experience is particularly valuable for users who want to trade tokens on chains where they don't hold native assets.

How Intent-Based Swaps Work (Fusion & Fusion+)

Resolvers are third-party actors who fill user swap intents on Fusion and Fusion+. You create an "order intent" that specifies what tokens you want to trade and your target price range. That intent enters a Dutch auction where resolvers compete to fill your order. This auction mechanism ensures competitive pricing by allowing multiple resolvers to bid for the right to execute your trade.

When a resolver accepts the terms, it pays gas fees, pulls liquidity from DEXs or major trading platforms, and completes the swap on-chain. If the order expires without a match, it cancels automatically — your funds remain safe. This fail-safe mechanism protects users from unfavorable market conditions or insufficient resolver participation.

Fusion+ extends this same process to cross-chain swaps. You sign an intent that names a destination chain and an acceptable rate. Resolvers must lock source-chain tokens into an escrow contract and lock target-chain tokens into a second escrow. Both escrows rely on a shared secret hash and a timelock, creating a trustless atomic swap mechanism.

Once both sides confirm, the secret reveals, and the resolver finalizes the swap atomically. You never lose custody of funds unless the swap completes. This atomic execution model eliminates counterparty risk and ensures that cross-chain trades are either fully completed or safely reversed.

Simple mode is ideal for users who want the best price with one click and no distractions. It abstracts away the complexity of DeFi trading while maintaining the security and efficiency benefits of decentralized execution.

Advanced Mode

Advanced mode brings along the full suite of 1inch features for experienced traders. In this mode, you get access to live price charts, trade route details, and advanced swap settings. This comprehensive interface allows traders to make informed decisions based on real-time market data and execution parameters.

You can view how 1inch splits your trade across multiple liquidity sources and adjust parameters such as slippage tolerance, route priority, partial-fill allowance, and preferred gas token. This level of control enables sophisticated trading strategies and risk management approaches that are not possible in simple mode.

Advanced mode lets you choose Classic swap execution and adjust advanced settings. For those out of the loop, Classic swap uses the Pathfinder algorithm to split orders across liquidity sources with detailed visualization in the UI. The visual representation of trade routes helps traders understand exactly how their orders are being executed and which liquidity pools are being accessed.

Advanced mode is best suited for analyzing routes, adjusting trade parameters, and fine-tuning executions. Professional traders and those managing larger positions will find the additional control and transparency valuable for optimizing their trading outcomes.

Limit Orders

1inch's Limit Order feature allows users to place trades at specific target prices, which allows them greater control over execution. This functionality brings traditional order book trading mechanics to the decentralized environment, enabling more sophisticated trading strategies.

Put simply, a Limit Order stays open until the market reaches your specified conditions instead of filling immediately at market price. The system, powered by the 1inch Limit Order protocol, enables fee-free order placement. This means you can set your desired entry or exit points without paying gas fees upfront.

You can specify the token, price, and expiration time (e.g., sell 1 ETH if it reaches 5,000 USDC). Orders are held off-chain and filled only when the conditions are met, meaning no gas is required to place them. This off-chain order book approach significantly reduces the cost of managing multiple orders and allows for more flexible trading strategies.

Limit orders are available in advanced mode under the corresponding tab. They integrate seamlessly with the platform's other features, allowing traders to combine limit orders with other execution modes as part of a comprehensive trading strategy.

Limit orders are especially useful for automating trades at optimal prices without active monitoring, reducing both gas usage and slippage compared to manual execution. They are particularly valuable in volatile markets where timing and price precision are critical.

The 1inch Fusion Protocol: Intent-Based Gasless Swaps

One of 1inch's most powerful aspects is the Fusion protocol, which introduced intent-based, gasless swaps to DeFi. This innovative approach represents a significant evolution in how decentralized trading is executed, moving away from direct transaction submission toward a more efficient intent-based model.

In Fusion mode, you can swap tokens without paying gas fees or dealing with miner extractable value attacks — a major advantage for on-chain traders. This gasless execution model removes one of the primary barriers to DeFi adoption and makes trading more accessible to users across different experience levels.

Fusion allows users to create an "order intent" that specifies what they want to trade and under what conditions (instead of executing a swap directly through a DEX at the current price). This intent functions like a flexible limit order with a price range and time window. Once signed, the order is passed to resolvers — professional market makers — who compete to fill it.

Resolvers pay the gas fees to complete the swap on-chain, so users don't need native chain tokens like ETH or BNB to cover gas. Fusion uses a Dutch auction model to determine pricing. Initially, the price favors users, and over time it shifts toward the resolver's price target. This design incentivizes resolvers to fill orders early, encouraging them to act quickly to secure a better profit margin while still honoring the user's price limits.

If the order reaches the end of the time window without being filled at acceptable terms, it expires without execution. This automatic expiration mechanism protects users from unfavorable market conditions and ensures that orders are only executed when they meet the specified criteria.

When resolvers do execute, they pull liquidity from DEXs, centralized platforms, and internal inventory, thereby giving users access to deep, distributed liquidity. Even large orders can be filled in parts by multiple resolvers to reduce slippage. This fragmented execution approach often results in better overall pricing than single-source execution.

Gasless execution is a key benefit. Resolvers bundle your trade into their own transactions and earn arbitrage or spread, while you only pay the swap amount and a small fee included in the rate. This fee structure is typically more favorable than paying gas fees directly, especially during periods of network congestion.

MEV Protection

MEV (Maximal Extractable Value) refers to the profit a validator or miner can gain by reordering, inserting, or excluding transactions within a block. This often results in front-running or sandwich attacks that worsen trade outcomes for regular users. These attacks can significantly impact trade execution, particularly for larger orders or during volatile market conditions.

Fusion also protects users from MEV attacks like front-running or sandwiching. Because the order is filled by a resolver and submitted as a private, bundled transaction, MEV bots in the mempool never see it. This privacy layer is crucial for maintaining fair execution and preventing value extraction by malicious actors.

Some resolvers use private execution channels to further prevent any manipulation. This ensures a fairer trading environment, even for large swaps. The combination of private order handling and resolver competition creates a robust defense against various forms of MEV exploitation.

Fusion vs. Classic Swaps

Before Fusion, 1inch swaps used a "classic" model, where trades were executed immediately and the user paid gas. Classic mode is still available and useful when instant, guaranteed execution is needed. This traditional approach remains relevant for certain use cases where immediate execution is more important than gas optimization.

However, the Fusion protocol has become the default option for Simple mode because it often provides better outcomes after factoring in gas and MEV. The combination of gasless execution, MEV protection, and competitive resolver pricing typically results in superior net returns for users.

1inch's in-house analysis claims that users save around 9.5% compared to competitor swaps using Fusion — primarily due to gas savings and execution optimization. This significant cost reduction makes Fusion particularly attractive for frequent traders and those executing multiple swaps across different chains.

Cross-Chain Swaps with Fusion+

Cross-chain interoperability has long been a challenge in DeFi. Traditionally, swapping tokens across chains required using bridges or centralized platforms — both of which were slow, somewhat expensive, and introduced custodial risks. These traditional methods also required users to manage multiple interfaces and maintain balances on different chains.

Fusion+ changes that by enabling relatively easy, bridgeless cross-chain swaps within the platform. You can swap tokens from one chain to another (e.g., Ethereum to BNB Chain) in a single step without relying on third-party bridges or custodians. Importantly, you retain full self-custody at all times.

The process is atomic, meaning the swap either completes in full or fails with a refund — no partial outcomes. This atomic execution guarantee is crucial for maintaining security and user confidence in cross-chain operations.

How Fusion+ Works

Fusion+ is built on atomic swap principles using 1inch smart contracts and resolvers. You sign an order intent specifying the token destination chain and acceptable rate when initiating a cross-chain swap. This intent-based approach maintains the same user-friendly experience as single-chain swaps while handling the additional complexity of cross-chain execution behind the scenes.

The intent is shared with resolvers, who monitor a Dutch auction where the price gradually drops over time. They monitor the auction with the aim of filling the order as soon as the price meets their profit target. The first resolver to accept the terms wins the auction and locks your tokens into an escrow contract on the source chain.

Simultaneously, the winner locks the target-chain tokens (from their own funds) into a second escrow on the destination chain. Both escrows use a shared secret hash and a time lock. This dual-escrow mechanism ensures that both parties fulfill their obligations or the trade is safely reversed.

Once both escrows are confirmed, the "secret" is revealed, which then allows the resolver to claim the tokens on one chain and send you the tokens on the other. The entire process is coordinated to be completed securely and atomically. This cryptographic coordination eliminates the need for trusted intermediaries while maintaining security.

Timelock and Safety

If something goes wrong — for instance, if the resolver fails to deliver — the swap cancels automatically after a set time window. Funds are returned to the original owners. Resolvers also post a small security deposit that they forfeit if they fail to follow through. This mechanism is there to protect you from incomplete or failed swaps.

The timelock mechanism serves as a critical safety feature, ensuring that neither party can hold funds hostage indefinitely. If the resolver does not complete their side of the swap within the specified timeframe, the escrow contracts automatically refund both parties. This automated recovery process eliminates the need for manual intervention or dispute resolution.

Fusion+ brings the reliability of atomic swaps into a user-friendly format, offering the same trustless guarantees but through a DeFi interface accessible to any user. The combination of cryptographic security and intuitive design makes cross-chain trading accessible to users who may not fully understand the underlying technical mechanisms.

Why Fusion+ Can Be a Game-Changer

With Fusion+, 1inch delivers a somewhat unique and practical feature in DeFi: cross-chain swaps that are secure, decentralized, and require no bridges. The process is simple — no juggling apps, no managing gas on multiple chains, and no exposure to bridge vulnerabilities.

For instance, swapping tokens from Ethereum to Polygon with Fusion+ is faster, safer, and cheaper than using a traditional bridge. You don't pay gas on the source chain because resolvers handle gas costs on both ends. This makes cross-chain trading as easy as a standard token swap.

The elimination of bridge dependencies also removes several attack vectors that have plagued DeFi in recent years. Bridge hacks have resulted in billions of dollars in losses, making bridgeless solutions like Fusion+ increasingly attractive to security-conscious users.

Fusion+ represents a major advancement in multi-chain DeFi infrastructure by removing reliance on custodial intermediaries and integrating atomic security. Fusion+ remains under the radar for many users, yet it redefines what cross-chain trading can — and should — look like: trustless, gasless, and bridge-free.

1inch Security: What Protects You While Swapping

The platform promises a comprehensive security stack to protect users from scams, hacks, and fraudulent activity at every step. This spans everything from smart contract audits to real-time address screening. Security is not just a feature but a fundamental design principle that permeates every aspect of the platform.

Here are some of the key layers of protection 1inch offers:

Blocklist Strategy: 1inch screens wallet addresses for risk, using data from TRM Labs, Etherscan, and its own investigation team. Suspicious wallets are blocked automatically. This proactive approach helps prevent users from inadvertently interacting with compromised or malicious addresses.

Transaction Simulations: The wallet shows you exactly what will happen right before you sign a trade. You see what tokens leave your wallet, what comes in, and if anything looks sketchy. This preview functionality helps users catch potential scams or unexpected outcomes before committing to a transaction.

Scam Protection: 1inch has teamed up with security platforms like Blockaid to detect threats such as malicious transactions, suspicious DApps, scam domains, and phishing attempts. You'll get an alert before connecting to anything flagged as unsafe. This multi-layered detection system leverages both automated scanning and community reporting.

Smart Contract Audits: Every contract used by 1inch has been audited multiple times. Put simply, they are also non-upgradable, so no surprise code changes can sneak in. This immutability provides strong guarantees about contract behavior and eliminates the risk of malicious upgrades.

Front-Running Protection: Fusion and Fusion+ prevent bots from manipulating your trade by hiding your order until it's executed. This protection is built into the protocol design rather than being an optional feature, ensuring consistent protection for all users.

AML Compliance: Resolvers must pass KYC checks before operating. Transactions are also screened for links to money laundering, scams, or hacked funds. This compliance layer helps maintain the platform's legitimacy while still preserving user privacy where appropriate.

Brand Protection: 1inch actively removes fake websites and social scams with help from Red Points and Phishfort. This way, you stay protected even outside the DApp. The team maintains vigilant monitoring of impersonation attempts and works quickly to take down fraudulent sites.

Additional Protection Layers on 1inch

Downtime Fallback: Fusion+ has a built-in recovery phase for stalled swaps. If a resolver fails to complete a swap, the system automatically initiates a refund process, ensuring users never lose access to their funds.

MEV Resistance: Private order handling eliminates sandwich attacks. By keeping order details private until execution, the platform prevents malicious actors from extracting value through transaction reordering.

Behavioral Risk Analysis: User actions are monitored to detect signs of compromise. Unusual patterns may trigger additional verification steps to protect accounts from unauthorized access.

1inch Swap vs. Alternatives

When comparing 1inch Swap to other aggregators and DEX platforms, several key differences emerge that highlight its unique value proposition:

Gasless Swaps: 1inch Swap offers gasless swaps through the Fusion protocol, while most other aggregators do not support this feature. This fundamental difference significantly reduces trading costs and removes barriers to entry.

Cross-Chain Swaps: 1inch Swap provides bridgeless cross-chain swaps via Fusion+, whereas alternatives usually require bridges. This bridgeless approach eliminates custodial risks and simplifies the user experience.

Swap Modes: 1inch Swap offers Simple, Advanced, and Limit Orders, while competitors are often limited to basic swapping. This flexibility allows users to choose the right tool for their specific needs.

Front-Running Protection: 1inch Swap includes native MEV resistance, while most alternatives rely on slippage controls. This built-in protection provides superior defense against value extraction.

Liquidity Depth: 1inch Swap aggregates from over 100 sources, while competitor aggregation is often limited to major DEXs. This deeper liquidity access typically results in better pricing, especially for larger orders.

Security Stack: 1inch Swap includes blocklists, AML, and scam detection, which are not always transparent or available on other platforms. This comprehensive security approach provides users with multiple layers of protection.

User Interface Options: 1inch Swap offers beginner to pro-friendly settings, while alternatives often have fixed or less customizable interfaces. This adaptability makes the platform suitable for users across different experience levels.

Permit2 Support: 1inch Swap fully supports Permit2, which is rare or partially implemented on other platforms. This support enables more efficient token approvals and improved security.

Governance Model: 1inch Swap operates under a community-led DAO structure, while most alternatives are centrally managed. This decentralized governance aligns with the broader ethos of DeFi and gives users a voice in platform development.

Potential Drawbacks

While 1inch Swap comes packed with practical and efficient features, there are a few potential drawbacks depending on your use case:

Delayed Execution in Fusion Mode: Because Fusion uses Dutch auctions, your swap might not execute instantly. If you need immediate execution, Classic mode may be better. The auction mechanism, while beneficial for pricing, introduces a time delay that may not suit all trading scenarios.

Limit Orders Depend on Taker Interest: Your order might not fill if it isn't profitable for resolvers or takers, especially with low-liquidity pairs. This dependency on resolver participation means that limit orders are not guaranteed to execute, even if the market price reaches your target.

Gas Fees in Classic Mode: If you use Classic swaps, you still need native tokens like ETH or MATIC to cover gas. This traditional gas requirement returns when opting out of the Fusion protocol, which may be necessary for certain time-sensitive trades.

Cross-Chain Swaps Are Resolver-Dependent: Fusion+ relies on resolvers to complete swaps. While protected by escrow and recovery mechanisms, it is not instant like native-chain swaps. The dependency on resolver availability and willingness to participate can occasionally result in longer execution times.

Complexity for New Users: Advanced settings, presets, and auction mechanics can feel overwhelming if you are used to simpler DEXs. The platform's extensive feature set, while powerful, requires a learning curve that may deter some beginners.

Is 1inch Swap the Right Fit for You?

As you can see, 1inch Swap offers far more than basic DEX aggregator functionality. If you are an active trader managing assets across chains, it can be a strong alternative to simpler platforms. The combination of gasless execution, cross-chain capabilities, and advanced trading features makes it particularly attractive for users who frequently trade or manage diverse portfolios.

That said, the multiple modes and advanced settings may feel complex for some beginners who may prefer easier tools for basic swaps. Additionally, Fusion mode's reliance on resolvers also introduces timing and pricing trade-offs. Users who prioritize immediate execution over cost optimization may find Classic mode or other platforms more suitable for their needs.

Overall, whether 1inch Swap suits your needs ultimately depends on how actively you trade and how much control you want. For experienced traders seeking maximum efficiency and flexibility, the platform offers compelling advantages. For casual users making occasional swaps, the learning curve and feature complexity may outweigh the benefits. Consider your trading frequency, asset diversity, and comfort level with DeFi protocols when deciding if 1inch Swap is the right choice for you.

FAQ

What is 1inch Swap? How does it differ from other DEX exchanges?

1inch Swap is a DEX aggregator that splits trades across multiple decentralized exchanges using smart contracts. Unlike traditional DEXs, it optimizes liquidity sources and reduces gas fees, delivering better prices and lower transaction costs for users.

How to swap tokens on 1inch? What are the detailed steps?

Connect your wallet to 1inch, select the token you want to sell and the token you want to receive, enter the amount, review the exchange rate and fees, then confirm the transaction to complete the swap.

1inch Swap的费用是多少？如何最小化交易成本？

1inch Swap不收取明面手续费，但存在隐性差价。最小化成本可选择较低交易额、低网络费用时段交易，并比较不同路由方案获得最优成交价。

Is swapping on 1inch secure? What risks should I be aware of?

1inch employs robust security measures and smart contract audits to protect users. While the protocol is generally safe, users should remain cautious of slippage, price volatility, and ensure they verify contract addresses before transactions.

Which blockchain networks and token pairs does 1inch support?

1inch supports Ethereum, BNB Chain, Polygon, Optimism, Arbitrum, Avalanche, Fantom, and Gnosis Chain. It enables trading across thousands of token pairs on these networks through its DEX aggregation protocol.

What are 1inch's liquidity sources? How does it aggregate multiple DEXs?

1inch aggregates liquidity from multiple decentralized exchanges like Uniswap, SushiSwap, Balancer, and Curve. It connects these platforms to find optimal trading routes and best prices across different liquidity sources simultaneously.