What is Across Bridge—and where is the catch?
Across Bridge moves tokens between supported blockchains by having a relayer deliver the destination asset first, then settle the transfer later. The catch is not a hidden flat toll: it is that the price, minimum, token received and fill time are route-specific. A quote that is excellent for USDC from Arbitrum to Base can be poor—or unavailable—for ETH from Ethereum to another chain.
The most expensive mistake is approving a transfer before checking the exact destination token, amount received and network. A wrong network selection can leave you with an asset you cannot use without paying for another swap and bridge; a stale quote can change the output or fail because gas, liquidity or route limits moved.
How fast is Across Bridge compared with its settlement clock?
A normal relayer fill is advertised at about 2 seconds on mainnet, while the relayer’s reimbursement bundle settles in roughly 1.5 hours. Those numbers describe different events: the recipient may receive funds almost immediately, but the protocol’s back-end settlement is not instant. Do not confuse fast delivery with final protocol accounting.
| Number | What it measures | What it means for a sender |
|---|---|---|
| ~2 seconds | Typical mainnet fill | Funds can arrive quickly when a relayer accepts the route. |
| ~5,400 seconds | 1.5-hour bundle settlement | Relayer capital remains exposed after you have been paid. |
| ~60 seconds | Deposit-status API latency | Status monitoring is useful, but it is not a block-by-block confirmation feed. |
| 23+ mainnets | Protocol chain coverage | Coverage is broad, but it does not mean every token works on every pair. |
| 8 testnets | Development coverage | Testnet availability is not a reason to send production funds. |
What does an Across Bridge transfer actually cost?
The all-in transfer cost is input amount − output amount. That gap can contain an LP fee, a relayer capital fee and destination-chain gas; an app can also add its own fee. There is no honest universal percentage because utilization, token, amount, destination gas and the relayer’s repayment chain change the quote. LP cost can be zero when the relayer takes repayment on the origin chain, because no cross-chain rebalancing is needed.
Use Across Bridge only after treating the displayed output amount—not a headline fee rate—as the number that matters. Compare the destination amount with the amount you would receive through your alternative route, including any destination swap you would otherwise need.
Which Across Bridge limits can stop a transfer?
Every quote has a route-specific minimum and maximum. A small transfer can be rejected because destination gas consumes too much of it; a large transfer can exceed instant-fill capacity and wait for a short-delay fill. The protocol also sets a fill deadline, and some deposits give one relayer exclusive fill rights until an exclusivity deadline. That temporary exclusivity is designed to encourage a fast fill, but it means “submitted” is not the same as “received.”
How do you bridge with Across Bridge without the common error?
- Connect the wallet that holds the source-chain asset and switch it to the source network.
- Select the destination network first, then select the asset you need there; do not assume matching ticker symbols are interchangeable.
- Enter the amount and inspect input token, destination token, recipient address, output amount, fee breakdown, minimum/maximum and estimated fill time.
- Most often missed: confirm the destination network in the wallet and that the displayed output is enough for the next transaction. Receiving USDC is not the same as receiving the native gas token needed to use that chain.
- Immediately before approval, check the Across Bridge live quote; it should show the current route, expected output and execution conditions.
- Approve only the required token allowance, submit the deposit, then monitor the transaction until the destination fill is confirmed.
What must be true before sending funds across?
- The source chain, destination chain and token contract are exactly the intended ones.
- The recipient address is controlled by you or independently verified.
- The quoted output amount, not just the fee percentage, is acceptable.
- The route’s minimum and maximum permit the amount.
- You will have enough destination gas—or the correct token—to complete your next action.
- You understand that a two-second estimate is not a guarantee during congestion or limited liquidity.