Fastest Crosschain Swap: How Relay Executes in Seconds

Mar 27, 2026

A crosschain swap that takes minutes is a crosschain swap that loses money. Yield windows close, arbitrage spreads collapse, and gas conditions shift - all while assets are in transit between chains. Speed is not a convenience feature. It is the difference between a successful operation and a missed one.

Relay executes crosschain swaps with a 2.7-second median across 85+ chains and $20B+ in processed volume. That speed is not the result of cutting security corners. It comes from a specific architectural decision: intent-based execution with competitive fillers.

This article explains the execution pipeline that makes Relay the fastest crosschain swap protocol, and why that speed matters for what users can do onchain.

What Makes a Crosschain Swap Fast

Speed in crosschain execution is determined by one question: does the user wait for cross-chain settlement?

In traditional models, the answer is yes. A lock-and-mint protocol locks assets on the source chain, passes a message to the destination chain, waits for that message to be verified, and then mints or releases assets. Each step adds latency. Message verification alone takes minutes — sometimes longer depending on the chains involved and the security model.

In intent-based models, the answer is no. The user declares what they want (the intent). A solver delivers the result immediately from pre-positioned inventory. Settlement between chains happens afterward, asynchronously. The user is already holding their destination assets while the protocol reconciles.

This is the structural reason intent-based protocols are faster. They decouple user experience from settlement finality.

Relay's Execution Pipeline

Relay's architecture processes a crosschain swap through four stages. The user-facing portion — from confirmation to receiving assets — typically completes in under three seconds.

1. Quote

The user specifies their desired swap: source asset, source chain, destination asset, destination chain, and amount. Relay's solver network returns a quote that includes the exact output amount, all fees, and estimated execution time.

The quote reflects real-time competition between fillers. Multiple fillers evaluate the order and submit competing offers. The user sees the best available rate.

2. Order

The user confirms the quote and signs a transaction from their wallet. This creates an on-chain order on the source chain that locks the user's input assets. The order specifies the exact output parameters — what the user should receive, where, and by when.

Relay is non-custodial throughout this process. The user signs from their own wallet, and the order contract enforces the terms.

3. Fill

A filler delivers the destination assets to the user's wallet on the destination chain. This happens from the filler's own inventory — pre-positioned liquidity on the destination chain. The filler does not wait for the source-chain transaction to finalize before delivering.

This is where the speed comes from. The filler takes on execution risk by fronting capital before settlement completes. In return, the filler earns the spread between the user's input and the cost of filling.

Multiple fillers compete for each order, which drives execution speed. A filler who waits loses the order to one who fills immediately.

4. Settle

After the user has received their destination assets, the protocol settles the source-side funds to the filler. Settlement uses cross-chain messaging to verify that the source-chain order was valid and that the filler delivered correctly.

Settlement can take minutes — but the user does not wait for it. From the user's perspective, the swap completed at step 3.

Why 2.7 Seconds

Relay's 2.7-second median execution time is the result of several reinforcing design choices:

Fillers pre-fund destination liquidity. Fillers maintain capital on destination chains in anticipation of orders. When an order arrives, the capital is already in position. There is no liquidity sourcing delay.

Competitive filler market. Relay's filler network includes sophisticated market participants who optimize for speed. Slower fillers lose orders to faster ones, creating a natural selection pressure toward faster execution.

Asynchronous settlement. By separating user-facing execution from inter-chain settlement, Relay eliminates the single largest source of latency in crosschain operations. Users receive assets in seconds; settlement happens on its own timeline.

Gas abstraction. The filler handles all destination-chain gas. Users don't need to hold native tokens on the destination chain or execute a separate gas-funding step before the swap.

85+ chain coverage. Relay's filler network covers a broad range of chains, which means fillers can maintain efficient inventory across the network rather than being bottlenecked on thin routes.

The 2.7-second figure is a median across all supported chains and transaction sizes. Individual swaps between well-serviced routes (e.g., Ethereum to Base, Solana to Arbitrum) frequently complete in under two seconds.

What Fast Execution Enables

Sub-3-second crosschain execution changes what is practically possible onchain:

DeFi composability across chains. When moving between chains takes seconds, multi-chain DeFi strategies become viable in real time. A user can rebalance a portfolio across Ethereum, Base, and Arbitrum in the time it previously took to complete a single crosschain operation.

Real-time portfolio management. Crosschain execution that takes minutes forces users to plan ahead and tolerate slippage during the wait. Seconds-fast execution turns crosschain rebalancing into something that can be done reactively, in response to changing conditions.

Application-layer integration. Apps and wallets that embed Relay (including OpenSea, Phantom, and MetaMask) can offer crosschain functionality that feels native. Users don't leave the app or wait for a separate process to complete. The swap is fast enough to feel like a same-chain operation.

Arbitrage and market efficiency. Faster crosschain execution means price discrepancies between chains correct more quickly. This benefits all users through tighter spreads and more consistent pricing.

How Relay Compares

Aggregators that route through multiple hops can sometimes find competitive rates, but each hop adds latency and potential failure points. Relay's direct intent-based model avoids multi-hop complexity entirely.

Frequently Asked Questions

Is 2.7 seconds the guaranteed execution time?

2.7 seconds is the median across all chains and transaction sizes. Most swaps on high-liquidity routes complete in 1–3 seconds. Occasionally, less common routes or very large orders may take slightly longer. The quote shown before confirmation includes an estimated execution time.

How does Relay execute so fast without compromising security?

Speed comes from the filler model, not from relaxing security. Fillers front liquidity from their own inventory and settle afterward. The user receives native tokens directly to their wallet. Relay is non-custodial — the protocol coordinates but never takes custody of funds.

What happens if a filler doesn't deliver?

The order contract enforces delivery. If a filler fails to deliver within the specified timeframe, the user's source-side funds are returned. In practice, Relay maintains a 99.9%+ fill rate across 100M+ transactions.

Can I use Relay for large transactions?

Yes. Relay's filler network supports transactions across a wide range of sizes. Larger orders may see slightly different pricing due to liquidity depth, but the execution model is the same. The quote reflects the exact terms before you confirm.

Which wallets work with Relay?

Relay supports any EVM wallet (MetaMask, Rainbow, Coinbase Wallet) and Solana wallets (Phantom, Backpack). Connect directly at relay.link — no account creation required.