Cross-chain · Avalanche C-Chain → Base

Swap USDC from Avalanche C-Chain to ETH on Base

Swap USDC from Avalanche C-Chain to ETH on Base. Circle USDC leaves C-Chain, and native ETH is what can arrive on Base, where it pays gas on that L2.

You spend Circle at 0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E on Avalanche C-Chain, chain id 43114. Snowtrace is the source explorer. The ETH you can receive is 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, the native gas sentinel, on Base, chain id 8453. Basescan shows it as ETH, not as an ERC-20. Base is an Ethereum L2, but this balance is not mainnet ETH and it is not WETH at the 0x4200 predeploy.

Diagram for Swap USDC from Avalanche C-Chain to ETH on Base
USDC leaves Avalanche C-Chain. ETH is what can arrive on Base.

Base gas is ETH, and this route is how you buy it

A Circle balance on C-Chain does not pay a Base transaction. Chain id 8453 wants ETH. The sentinel means that native coin, so you do not approve it. You also do not import it as a token. If the wallet is still on chain id 43114, you will keep staring at USDC and AVAX and miss the arrival. Switch to Base and read the ETH line on Basescan.

L2 ETH is not the 12 second mainnet balance

Ethereum is chain id 1. Blocks there are about 12 seconds, and the explorer is Etherscan. Base posts data back toward Ethereum, yet the ETH in a Base account cannot cover a mainnet approval. It also cannot cover Arbitrum or Avalanche. If the empty tank is on mainnet, this page fills the wrong tank. Base is the network note for the chain you would be funding.

The predeploy WETH is a different job

Base WETH sits at 0x4200000000000000000000000000000000000006. Several other rollups reuse that predeploy address, and the balances are still not shared. Native ETH from this quote will not satisfy a contract that names the predeploy. WBTC is unrelated and is not native bitcoin. If the app wants wrapped ether, change to the WETH route before you approve Circle's USDC.

AVAX has to survive the exit

The source fee is AVAX, not USDC. Bridged USDC.e on Avalanche is not 0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E. X-Chain funds do not sign this. Approve only the Circle contract the quote names. Dollar-to-ETH prices move, so treat the minimum ETH as a hard floor. A C-Chain block and a Base block do not add up to a promised delivery time.

Legal

Risk disclosure

XAUConnect is a non-custodial swap aggregator. Digital assets are volatile and may lose value rapidly. Content on this page is educational and not investment advice. Verify every contract address on the official block explorer before approving a transaction.

Frequently asked questions

What is the best way to swap USDC from Avalanche C-Chain to ETH on Base?

You spend Circle at 0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E on Avalanche C-Chain, chain id 43114. Snowtrace is the source explorer.

Is ETH on Base the same as ETH on Ethereum?

No. Circle USDC leaves Avalanche and native ETH arrives on Base, chain id 8453, quoted as 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE. Ethereum is chain id 1, about 12 second blocks, explorer Etherscan. Basescan is the check for this arrival. The two ETH balances do not pay each other's fees. AVAX paid the source side.

Will this route deliver Base WETH?

No. The arrival is native ETH, the gas token. WETH is the predeploy at 0x4200000000000000000000000000000000000006, and that is a different route. If a pool rejects native ETH, this page is wrong. You would still need ETH afterward to wrap. Confirm the native balance on Basescan.

Which USDC contract is spent on C-Chain?

Circle's native USDC at 0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E, chain id 43114. Snowtrace is the explorer. Bridged USDC.e will not match, and X-Chain AVAX is not a source. Keep AVAX for the fee. An approval should name this Circle contract and the spender from the quote. The quote minimum is the floor, and a thin floor is a reason to stop.

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