What Is a Crypto Bridge? Cross-Chain Transfers Explained

You have just bought some Ethereum and it is sitting in your wallet. Then you see a new DeFi app or blockchain game that everyone is using.

There is a catch. This new app runs on a different blockchain, like Solana or Arbitrum. Since each blockchain is its own network with its own rules, your ETH cannot just jump across. It is stuck on its home chain.

To use that app, you need a way to move the value of your ETH to the other network. That is what a crypto bridge is for.

What is a blockchain bridge?

Think of blockchains as separate islands. The Bitcoin island has its own money, rules, and economy. The Ethereum island is another landmass with its own money and programming language.

For years, these islands could not talk to each other. A boat leaving Bitcoin island had nowhere to land on Ethereum island.

A blockchain bridge works like a ferry or a tunnel between these islands. It creates a communication channel so users can move tokens, data, and smart contract instructions from one chain to another.

Without bridges, crypto would stay split into small, isolated pools of liquidity. Any time you wanted to switch chains, you would need to sell your Bitcoin for dollars, then buy Ethereum with those dollars. Bridges make this smoother, cheaper, and keep the value inside crypto instead of going back through your bank.

How bridges work in practice

Under the hood, bridge tech is complicated. The good news is that, as of 2026, the user experience is much simpler thanks to new intent-based systems. It is still useful to know the three main ways bridges move value.

1. The Lock and Mint model

The most traditional design is called the Lock and Mint model. When you send a token across this kind of bridge, the original coin does not actually move to the new chain.

• Locking: You deposit your asset, such as Bitcoin, into a smart contract on the source chain. This contract acts like a digital vault.
• Verifying: The bridge protocol checks that the funds are locked and cannot be spent.
• Minting: The bridge then creates, or "mints," an equal amount of a wrapped token on the destination chain.

If you deposit Bitcoin, you might receive Wrapped Bitcoin (wBTC) on Ethereum. This wrapped token is basically an IOU. It is a claim on the Bitcoin that is sitting in the vault.

When you want to go back, the wrapped token is burned, which means destroyed, and your original Bitcoin is released from the vault.

Note: While wBTC is a well-known example of this model, it specifically relies on centralized custodians to manage the locked Bitcoin, which adds an additional trust layer. Not all Lock and Mint bridges use this centralized approach. Some use decentralized smart contracts or validator networks instead.

2. The Burn and Mint model

A newer and often safer approach, used by stablecoin issuers like Circle, is the Burn and Mint model.

Instead of locking funds in a central vault, the token on the source chain is permanently burned. Then the issuer mints a fresh, native token on the destination chain. There is no giant pool of locked funds, so there is a smaller target for hackers.

3. Intent-based bridges (the modern standard)

The biggest recent shift in bridge design is intent-based architecture. Older bridges made users manage a string of technical steps. With intent-based bridges, you just say what you want to happen.

For example, you might set an instruction like: "Send 100 USDC from Ethereum to Arbitrum."

Behind the scenes, a group of specialized agents, called solvers, compete to fill your request. They use their own money to pay you on the destination chain right away, often within seconds. The protocol then pays them back later.Some bridge aggregators now incorporate intent-based routing automatically.

This setup is usually faster and cheaper than older models, and it feels much closer to a simple transfer than a complex chain of crypto operations.

Why use a bridge?

Bridges do more than shuffle money around. They give you access to tools, apps, and opportunities that only exist on other networks.

Most people use bridges for three main reasons.

Lower transaction fees

On busy days, some major blockchains can get very expensive. Many users bridge their assets to Layer 2 networks or other chains to cut their transaction fees.

This is especially helpful if you make lots of smaller trades, run trading bots, or interact with DeFi on a daily basis.

Speed

Active traders move assets to fast networks to enter and exit positions quickly. Gamers do the same so their in-game actions confirm almost instantly instead of waiting on a slower chain.

Access to exclusive apps

Many decentralized apps (dApps) only exist on one or two chains. If the game you want to play lives on a specific sidechain, or the lending app you like is on Avalanche, you need a bridge to get your funds there.

Without a bridge, you would have to cash out, move through your bank, then buy back in on the other network. That is slower, more expensive, and adds tax and compliance complexity.

Real-world examples

Here are some of the better known bridge-related projects and ideas you might see.

Wrapped Bitcoin (wBTC)

Wrapped Bitcoin is a classic Lock and Mint use case. Bitcoin does not support complex smart contracts by default. By bridging BTC to Ethereum, users receive wBTC, an ERC-20 token that fits neatly into Ethereum's system.

With wBTC, you can use your Bitcoin in Ethereum-based lending apps, liquidity pools, or decentralized exchanges, instead of just letting it sit in a wallet.

Circle's Cross-Chain Transfer Protocol (CCTP)

Circle's Cross-Chain Transfer Protocol (CCTP) uses the Burn and Mint model to move USDC, a US dollar stablecoin, between blockchains.

When you bridge, you do not get "wrapped USDC." You get native USDC on the destination chain. In 2025, Circle launched CCTP V2 with "Hooks," which let users move funds and perform an action, such as a swap or deposit, in one step.

Bridge aggregators

You do not always have to pick a specific bridge yourself. Aggregators like Li.Fi, Bungee, or Jumper can check many bridges and routes at once.

They look for the route that best balances speed, cost, and security for your transfer. Think of them like travel comparison sites, but instead of flights, they compare bridge routes.

Risks and red flags

Bridges can be very useful, but they also come with extra risk. In fact, bridge-related hacks have made up a large share of total crypto losses in past years. In terms of crypto hacks, Q1 2025 was unfortunately the worst quarter on record. with Immunefi estimating US$1.64 billion lost.

Bridges are powerful, but they add extra risk compared to staying on a single chain. Bridge hacks have made up a large share of total crypto losses over the past few years.

Here are the key risks to understand.

The honeypot risk

In traditional Lock and Mint bridges, the smart contract often holds a very large balance of crypto. That single pool of funds becomes a prime target for hackers.

If an attacker finds a bug in the smart contract and drains the vault, the wrapped tokens on the other chain lose their backing. In a severe case, they can become worthless because there is no real asset left behind them.

De-pegging

Wrapped tokens are meant to follow the price of the original asset at a 1:1 rate. If the original asset is worth $1,000, the wrapped version should also trade for $1,000.

If a bridge loses user trust or gets exploited, that peg can break. The wrapped token can start to trade below the value of the real asset. This is called de-pegging.

In that situation, you may not be able to redeem your wrapped tokens for full value, or you may be forced to accept a discount if you sell on the open market.

Smart contract vulnerabilities

Bridges rely fully on code. If the code that controls deposits, withdrawals, or message passing has a bug, funds can be frozen, stolen, or lost for good.

Before you use a bridge, it is smart to:

• Check if the protocol has audits from well-known security firms.
• Look at how long it has operated without major incidents.
• Review how much value is currently locked and whether that has changed sharply over time.
• Read community feedback and incident reports, not just the project's own marketing.

The future of multichain

Crypto is moving toward a future where "bridging" fades into the background. Many people call this idea chain abstraction.

In a perfect version of this future, you would just use an app. Your wallet or the protocol would handle all the cross-chain transfers behind the scenes. You would not need to think about which chain you are on, just like you do not think about which data center holds your email.

Intent-based systems and smarter aggregators are early steps in this direction. They hide some of the complexity and make moving between chains feel more like using a normal financial app.

Until that future fully arrives, it is important to understand how bridges work, what can go wrong, and how to judge the risk for yourself. Knowing the basics can help you use multichain tools without putting more on the line than you expect.