Bospora

Stuck on a chain with no gas

Send a little native token to a chain where your wallet has none, paid from a chain where it still has some.

Read this first — it will not work for everyoneThis top-up is itself a transaction, so it has to be paid for from a chain where you still have gas. If every asset you own sits on the one chain where you have none, your wallet cannot sign anything there and no tool can fix that for you — you need someone to send you a small amount of that chain's native token, or to withdraw some from an exchange.

What each chain needs

Recommended balances, cheapest first. These are live figures, not rules of thumb — they track each network's current gas price.

ChainRecommended balanceWorth
OP Mainnet0.00000913 ETH$0.02
Avalanche C-Chain0.00403 AVAX$0.03
Scroll0.0000118 ETH$0.03
Base0.0000205 ETH$0.05
Arbitrum One0.0000272 ETH$0.07
Polygon PoS1.37 POL$0.13
BNB Smart Chain0.000177 BNB$0.13
Ethereum0.0000563 ETH$0.14
zkSync Era0.00033 ETH$0.84
Linea0.00166 ETH$4.19

Linea asks for roughly 210× what OP Mainnet does — the figures move with each network's gas price.

Why the spread is so wide

A rollup pays to publish its data to Ethereum, and how it does that decides what it charges you. Chains that post compressed data cheaply can charge users fractions of a cent; ones that post more, or that have not optimised it yet, have to pass the cost on. That is the whole reason the same transaction can cost a hundred times more on one rollup than another.

It also means these numbers move. A chain that is expensive this week may not be next month, which is why the table above is requoted rather than written down once.

Common questions

Why can I see my tokens but not move them?

Every chain charges its own native token for transactions — ETH on Ethereum and the rollups, POL on Polygon, BNB on BNB Chain. Bridging USDC to a new chain moves the USDC and nothing else, so the wallet arrives holding value it cannot spend. Nothing is lost; it just needs a few cents of the local token.

How much do I actually need?

Usually a few cents. The table above shows the current recommendation per chain, which is enough for several ordinary transactions rather than exactly one.

Is there a cheaper way than this?

Often, yes. If you hold funds on a centralised exchange, withdrawing a small amount of the native token directly to the chain usually costs less than bridging it. This is the faster route, not always the cheapest one.

Is it safe to connect my wallet?

Connecting only lets Bospora read your address and propose a transaction. Nothing moves until you approve it in your own wallet, and the site never holds your funds at any point.

Moving something larger than gas money? Compare what each route costs first, or check a transfer you have already sent.