zkSync Bridge

zkSync Bridge is the canonical route for moving ETH and standard ERC-20 tokens between Ethereum Layer 1 and ZKsync Era in both directions. It is a message-based bridge, not a liquidity bridge: there are no pools, relayers fronting you funds, or market makers in the route, and the protocol's own bridge contracts handle the asset. Third-party liquidity routes use automated market makers or other destination-side liquidity, so they have different pool, routing, and counterparty mechanics.

The canonical bridge does not swap tokens: deposit USDC and you receive USDC's Era representation. An asset's Era contract address differs from its Ethereum address, and rebasing tokens or tokens needing custom bridge logic are not supported by the default ERC-20 bridge. The Portal is the standard interface for the protocol's bridge contracts.

Bridging uses a lock-and-credit deposit and a burn-and-release withdrawal. A deposit locks the asset in the L1 bridge contract and emits an L1-to-L2 message; after ZKsync Era processes it, the corresponding asset is minted or credited to your recipient address on Era. A withdrawal burns the Era representation, sends an L2-to-L1 message into a rollup batch, and releases the funds on Ethereum only after batch execution, the withdrawal delay, and proof submission; that fast-in, slow-out asymmetry is part of the ZK-rollup model.

ERC-20 deposits usually require two signatures: an approval and then the deposit. The approval gives the bridge contract permission to move your token; the ERC-20 approval interface supports an allowance, so choose the amount you actually intend to bridge rather than an unlimited allowance when your wallet offers that choice.

To deposit to ZKsync Era, connect your wallet on Ethereum mainnet (chain ID 1), choose the asset and amount, confirm the recipient, and sign. The recipient defaults to your own address but can be any Era address; the deposit completes once the L1 transaction is included and Era processes the inbound message, which commonly takes minutes rather than hours.

ERC-20 is the token standard behind the approval step. Keep ETH on Ethereum for the deposit transaction because the L1 gas and L2 execution funding both come out of it. ETH is Era's native gas token, so bridging ETH provides destination gas; bridging only an ERC-20 leaves it unable to move until ETH arrives, making a small ETH deposit alongside the first token deposit the practical setup.

To withdraw back to Ethereum, burn the asset on Era and wait for the L2-to-L1 message to travel with a rollup batch. Funds become claimable on Ethereum only after the batch is executed and the protocol's withdrawal delay — currently a three-hour minimum — has elapsed; a proof then finalizes release to your L1 recipient.

A pending withdrawal is normal, so track the batch status and act on L1 only when the withdrawal is claimable. Submitting it twice burns two lots of Era gas and creates two claims. A third-party liquidity bridge is the faster exit when waiting is unacceptable, but it uses a different mechanism with its own trust assumptions rather than accelerating this canonical withdrawal.

Deposits cost Ethereum gas for the L1 transaction, which also funds the L2 execution of the deposit message; withdrawals cost Era gas to initiate, and finalization on Ethereum may require L1 gas to submit the proof. Network conditions move every figure, so the Ethereum gas fees estimate shown by your wallet at signing time is the number to use.

The canonical route has no liquidity or relayer fee because there is no pool or relayer to pay. Third-party bridges price differently, usually with a provider or protocol fee on top of gas for immediate destination-side delivery. You do not need the ZK token for this flow; ETH pays gas on both networks.

The canonical route uses validity proofs, publishes rollup data to Ethereum, and has undergone audits, but audited code does not remove smart-contract risk. Upgrade and governance permissions can change behavior, operators are involved in batch submission, and the practical failure points are the site, network, and approval you authorize.

Before signing, open the portal from a source you trust, confirm the wallet network and recipient, and verify that the transaction targets the bridge contract rather than an unknown approval. If a bridge asks for your seed phrase, requests an unlimited approval to an unknown contract, or arrived via a DM or ad, close it; legitimate bridging never needs your recovery phrase. Phishing guidance describes impersonating a trusted service to request sensitive information as social engineering. This dashboard is informational and holds nothing; during bridging, the protocol contracts lock or represent your assets while your keys stay in your wallet throughout.

Most bridge problems map to the wrong network, missing destination gas, an unlisted token contract, or a withdrawal that is still in the protocol queue. Wrong network: use Ethereum mainnet for deposits and Era (chain ID 324) for withdrawals. No destination gas: if you bridged only a token to a fresh Era address, send a small ETH deposit to that same address before trying to move it. Token not visible: the Era contract address differs from the L1 address, so add the correct Era token contract to your wallet.

Withdrawal pending for hours: check batch status and wait for the delay and proof; a slow canonical withdrawal is not a second withdrawal to submit.