A bridge can involve two gas fees, one for each chain, but you usually pay only the source fee yourself. The destination fee depends on whether the bridge completes the transfer for you or leaves you to claim it. Check that detail before confirming; it decides which native coins your wallet may need.
Each chain charges for its own transaction
Gas is the fee a blockchain charges to process an action. You pay it in that chain’s native coin: ETH on Ethereum, SOL on Solana. A bridge transfer can require one transaction on the source chain and another on the destination chain, so each network has its own fee.
A relay bridge can have a relayer, a service that carries a transfer message to the destination chain, submit that second transaction for you. That may spare you from holding the destination coin just to receive funds. The source transaction still needs approval and a fee in the source chain’s coin.
The network fee is separate from any bridge fee. A bridge may charge for its service, or a token swap may include a price difference. Read the wallet’s fee summary for each amount before you confirm; a single “total” can hide what goes to the network and what goes to the service.
The destination fee depends on how the transfer finishes
You may need destination gas if you must claim the funds yourself or make another transaction after they arrive. An automatic transfer may have a relayer submit the destination transaction and include its cost in the quote. The bridge’s steps and quote tell you which case applies.
For example, say you send USDC from Ethereum to Solana. Your wallet asks you to approve a source transaction and pay its fee in ETH. Once the transfer message is ready, the bridge may deliver the USDC to your Solana wallet automatically. You can receive it without SOL, but you will need SOL to send or swap it later.
Solana’s base transaction fee is 5,000 lamports per signature; a lamport is one-billionth of a SOL. Optional priority fees can add to it. The actual fee shown in your wallet can vary with the transaction and network conditions, so use that estimate rather than assuming every Solana action costs exactly the base fee.
Check the quote and destination step before sending
Before approving, check the source fee, the bridge’s fee, and whether the destination action is automatic or manual. Confirm the destination address and chain, too. A correct address on the wrong network can leave you without the expected funds.
If the bridge requires a manual claim, keep enough of the destination chain’s coin for that transaction. If it completes delivery for you, you can receive first and add gas later. A relay bridge changes who submits the destination step, so the deciding detail is whether your transfer needs a claim or follow-up action.
Choose differently if you plan to use the funds right away: arrange some destination gas before sending, or select a route that includes automatic delivery. If you only need to receive and hold the asset, check whether your wallet can receive it without destination gas.