How much does it cost to bridge crypto?
Three things make up the price of a bridge. Here's each one, in plain terms, and how to keep the total small.
The three costs of a bridge
Every cross-chain transfer has up to three cost components. Knowing them makes the quote you see in the widget easy to read:
- Network gas (on the source chain). The fee the blockchain charges to process the transaction that starts your bridge. This is the one that varies most — see the table below.
- Bridge / exchange spread. A liquidity bridge pays you out from a pool on the destination chain and takes a small cut or spread for sourcing that liquidity. It's usually a fraction of a percent.
- Service fee. Bridgeline adds a flat 0.5% fee, shown inside the quote before you confirm. It's how the site sustains itself, and it's never hidden.
What gas actually costs, by chain
Gas is the swing factor. As a rough guide, at time of writing:
- Ethereum: the expensive one — roughly a dollar to well over $20 for a swap when blocks are full.
- Base, Arbitrum, Optimism: typically a few cents.
- Polygon: usually a fraction of a cent (paid in POL).
- BNB Chain: usually well under a dollar (paid in BNB).
- Avalanche: low, but can rise with demand (paid in AVAX).
- Solana: fractions of a cent (paid in SOL).
The pattern is simple: if your funds start on a layer 2 or Solana, the gas portion is tiny. If they start on Ethereum mainnet, gas is the main cost — so it's often cheaper to bridge out of mainnet once and then transact on the other side.
A worked example
Say you bridge $200 of USDC from Arbitrum to Base. Gas on both sides is a few cents, the bridge spread might be a fraction of a percent, and the 0.5% service fee on $200 is about $1. Total: a couple of dollars, most of which is the service fee — not gas. The same transfer starting on Ethereum could add several dollars of mainnet gas on top.
Keeping it cheap
- Don't start bridges from Ethereum during congestion if you can avoid it.
- Batch — move a larger amount once rather than many small transfers.
- Bridge between layer 2s or to Solana directly instead of routing through mainnet.
- Always read the quoted total before you approve.
Common questions
How much does it cost to bridge crypto?
For most chains, a bridge costs a few cents of gas plus a small percentage taken by the bridge and the interface. The big variable is Ethereum mainnet, where gas alone can run from about a dollar to well over $20 when the network is busy. On layer 2s and Solana, total costs are usually a fraction of a percent.
Why do bridges charge a fee at all?
Liquidity bridges keep pools of tokens on both chains and pay you out instantly from the destination pool. The small spread or fee they take compensates for providing that liquidity and taking on rebalancing risk. Interfaces like Bridgeline add their own service fee on top, shown in the quote.
Is the cheapest route always the best?
Not always. The cheapest quote might be slower or use a less liquid path. Bridgeline surfaces the best available route, but you should still glance at the total — cost, estimated time, and the amount you'll receive — before you confirm.
How do I keep bridging fees low?
Avoid starting bridges from Ethereum mainnet during congestion, move larger amounts less often instead of many small transfers, and bridge between layer 2s or to Solana directly rather than routing through mainnet.
Next: how long a bridge takes and how bridging works.