Cross-Chain Swaps: What They Are and How They Work
Crypto exists across separate blockchain networks. Bitcoin, Ethereum, Solana, Tron, Arbitrum, and other networks have their own assets, addresses, and transaction rules.
Moving between these ecosystems isn’t as simple as sending one asset to an address on another network. Different infrastructure has developed to exchange value across them, including market makers, liquidity pools, intent-based systems, aggregators, and bridges. One way to exchange assets between these separate networks is through a cross-chain swap.
What is a cross-chain swap?
A cross-chain swap exchanges an asset on one blockchain for an asset on another. This is different from a same-chain swap, where both assets exist on the same blockchain.
| Swap Type | You have | You want | Pair Route |
|---|---|---|---|
| Cross-chain swap | SOL on Solana | BTC on Bitcoin | SOL to BTC → |
| Same-chain swap |  ETH on Ethereum |  USDC on Ethereum | ETH to USDC → |
| Cross-chain swap | BTC on Bitcoin | ETH on Ethereum | BTC to ETH → |
The exchange might look simple from the user’s perspective, but liquidity and settlement still have to be coordinated between separate blockchain networks.
Think of blockchains like different countries
Imagine you’re travelling to another country and need the local currency.
Traditionally, you might go to a bank or foreign exchange service, give them the currency you have, and receive the currency you need. You don’t need to personally find someone who has the currency you want and wants the exact currency you’re selling.
Cross-chain swaps provide a similar experience across blockchain networks. You start with an asset on one network and request an asset on another. The swap infrastructure handles the liquidity and execution needed to make that exchange possible.
For example:
- You have: BTC on Bitcoin
- You want: ETH on Ethereum
From your perspective, the exchange is simply:
BTC on Bitcoin → ETH on Ethereum
What happens behind the scenes depends on the cross-chain method being used.
How do cross-chain swaps work?
There isn’t one universal method for executing a cross-chain swap. Different protocols and services use different mechanisms to source liquidity and settle assets between blockchain networks.
Some of the main approaches include:
| Execution Approach | How It Works |
|---|---|
| Intent-based swaps | Let users specify the outcome they want while solvers compete to fulfill the request. |
| Cross-chain liquidity pools | Maintain liquidity across supported networks. Protocols such as THORChain use this model to facilitate swaps between native assets. |
| Aggregated routing | Searches across multiple protocols and liquidity sources to find a route between the source and destination assets. |
| Bridge and swap routes | Use a bridge as one part of the process before or after exchanging assets through available liquidity. |
| Just-in-Time (JIT) liquidity | Allows professional market makers to compete to provide liquidity and pricing when a swap is requested. An intermediate asset, such as USDC, can be used to connect liquidity between the source and destination assets. This is the model allblu currently uses. Liquidity is sourced in real time, while the user experiences the exchange as one cross-chain flow. |
These approaches work differently behind the scenes, but the goal is the same: exchange the asset you have on one blockchain for the asset you want on another.
See a cross-chain swap in action
Follow a complete swap from quote to settlement using live quotes.
How long do cross-chain swaps take?
The networks involved have different block times, confirmation requirements, and settlement characteristics. Below is how allblu’s live swap engine estimates typical settlement times across supported source networks:
| Network | Confirmation requirement | Typical allblu estimate |
|---|---|---|
| Bitcoin | 2 confirmations | 15 to 20 minutes |
| Bitcoin with Boost | 1 confirmation (eligible routes) | about 7 minutes |
| Ethereum | 1 confirmation | about 2 minutes |
| Arbitrum | 1 L2 confirmation | about 2 minutes |
| Solana | 1 slot finality | about 3 minutes |
| Tron | 19 confirmations | about 3 minutes |
Note: Estimates can vary by swap size, liquidity, network congestion, and destination network requirements.
Bitcoin routes can take longer because of network confirmation requirements. Eligible BTC Boost routes can reduce the required deposit confirmation stage when available.
The route matters too. Some cross-chain methods involve several underlying steps, while others coordinate liquidity and settlement within a single swap flow. Real-time quoting allows the estimate to reflect the specific assets, networks, liquidity, and conditions available when the swap is requested.
Check current cross-chain quotes →
Are cross-chain swaps the same as bridges?
No. A bridge and a cross-chain swap can both involve multiple blockchain networks, but they describe different actions.
A bridge generally moves an asset or representation of an asset between blockchain environments.
A cross-chain swap exchanges one asset on one network for another asset on another network.
A bridge can still be one component of a cross-chain swap route. Other cross-chain swaps can exchange native assets without requiring the user to manually bridge or wrap the source asset first.
CEX or DEX for cross-chain swaps?
Both centralized exchanges and decentralized cross-chain services can help you exchange assets across blockchain networks, but they offer different experiences.
Using a centralized exchange
A centralized exchange can be convenient if you already keep assets on the platform or want access to trading, fiat deposits, and other exchange services in one account.
The trade-off is that you generally need to create an account, complete any required identity verification, and give the exchange custody of your assets while they’re on the platform. CEXs also commonly offer order-book trading, fiat access, customer support, and more advanced trading features.
Moving between networks can also involve several separate steps:
Deposit → Trade → Withdraw
Fees can come from trading, spreads, deposits, or withdrawals depending on the exchange and route.
For some users, those extra steps are worthwhile for the convenience and services a centralized platform provides.
Using a decentralized cross-chain service
A decentralized cross-chain service generally allows you to keep control of your wallet rather than maintaining a custodial balance with a centralized exchange.
Typically, there is no exchange account or exchange-level KYC process required, although requirements can vary by service and jurisdiction. Self-custodial trading also introduces its own responsibilities, including managing wallets, addresses, gas, and transaction approvals.
Instead of separately depositing, trading, and withdrawing, a cross-chain swap can coordinate the exchange within one flow:
Asset in your wallet → Cross-chain swap → Asset in your wallet
Choosing between a CEX and DEX ultimately depends on your comfort level, available assets and liquidity, fees, and whether you value the convenience of a centralized platform or the control and self-custody of a decentralized service.
Frequently asked questions
What fees do cross-chain swaps have?
Cross-chain swap costs depend on how the swap is executed. They can include network fees, liquidity or trading fees, price impact, protocol fees, bridge fees, and service fees. The advertised fee alone doesn’t always show the full cost, so comparing the final amount received can give you a better picture. On allblu, fees are included in the quote so you can review the expected amount received before starting the swap.
Are cross-chain swaps safe?
Cross-chain swaps have different risks depending on how they’re executed. Bridge-based routes, liquidity protocols, market makers, and other execution models can each have different security assumptions. Always verify the source and destination networks, destination address, quote details, and minimum amount received before making a swap.
Do I need gas tokens to make a cross-chain swap?
It depends on how the swap is executed. Onchain cross-chain swaps generally require the native gas token of the source network. For example, sending USDC from Ethereum requires ETH for gas. On a centralized exchange, trades don’t require gas for each internal trade, although network fees may apply when depositing or withdrawing. With allblu, connected-wallet swaps are onchain, so you’ll need the appropriate gas token for the source network.
What happens if a cross-chain swap fails?
Failure handling depends on the service and where the transaction failed. Some swaps can return the source asset to a refund address, while other methods may require a recovery process. On allblu, a refund address is provided when required so eligible funds can be returned if the swap cannot complete.
Which blockchains support cross-chain swaps?
Support depends on the protocol, liquidity source, and swap service. Supporting a blockchain also doesn’t necessarily mean every token on that blockchain is available for cross-chain swaps. Allblu’s current available assets and networks can be viewed directly through the swap interface.
Do cross-chain swaps require wrapped tokens?
No. Some routes use wrapped or tokenized assets, while others can exchange supported native assets across their respective networks. A native cross-chain route does not necessarily require the user to manually wrap the source asset first.
Can I make a cross-chain swap from a crypto wallet?
Yes. Some wallets integrate cross-chain swap providers directly, while dedicated swap services can also let you fund a swap from your existing wallet. With allblu, supported swaps can be funded from a connected wallet or by sending funds to the unique deposit address generated for the swap.