Cross-chain · Base → Ethereum

Swap WETH from Base to USDC on Ethereum

Swap WETH from Base to USDC on Ethereum. Base WETH leaves chain 8453, and Circle USDC arrives on Ethereum mainnet.

The input is wrapped ETH at 0x4200000000000000000000000000000000000006, an ERC-20 you can open on Basescan. Native ETH, written as 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, is a different balance. If the wallet only holds the gas coin, this route has nothing to spend until you wrap. The output is Circle USDC at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Etherscan. Ethereum is chain 1, and blocks are about 12 seconds. That USDC has 6 decimals. It is not Tether and it is not Maker DAI.

Diagram for Swap WETH from Base to USDC on Ethereum — WETH leaves Base. USDC is what can arrive on Ethereum.

Allowance, then the hop

WETH on Base cannot be pulled until you grant the router an allowance. Read the spender and the cap. An unlimited allowance is optional, not required by the route. If you reject that signature, the swap cannot start. Native gas transfers do not ask for this, which is how you can tell the input is the wrapper. The approval itself is paid in ETH on chain 8453. Trade on Base is the network the wallet must show while you sign.

Circle on mainnet, six decimals

The arrival contract is the USDC address many desks already whitelist. Tether at 0xdAC17F958D2ee523a2206206994597C13D831ec7 will not pass that check, and neither will DAI. One USDC is 1,000,000 base units because the token uses 6 decimals. If an event log shows an 18 decimal integer, you are looking at a different contract than the one on this quote.

When the WETH route is a mismatch

Do not use this page if the Base balance is still native ETH. Do not use it to unwrap and keep ETH on Base. Do not use it for USDT or DAI. Do not use it if the USDC only needs to exist on Base for a local app. WBTC is not part of the trade, and WBTC would not be native bitcoin even if it were.

Ethereum fees are a separate coin

USDC cannot pay fees on chain 1. ETH spent as gas on Base does not reappear on Ethereum. Put a little ETH on mainnet before you plan to forward the USDC. Etherscan shows the credit only after the bridge completes, and this page does not time that wait. If the minimum USDC is below your floor, leave the quote unsigned.

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 WETH from Base to USDC on Ethereum?

The input is wrapped ETH at 0x4200000000000000000000000000000000000006, an ERC-20 you can open on Basescan. Native ETH, written as 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, is a different balance.

Does Base WETH need an approval on this route?

Yes. The input 0x4200000000000000000000000000000000000006 is an ERC-20, so the router needs an allowance before it can take the tokens. Native ETH, the 0xEeee placeholder, is not the input and is not approved. You still spend a little of that gas coin to pay for the approval and the send on Base.

Is the USDC that arrives the 6 decimal Circle token?

Yes. The destination is 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum, chain 1, which you check on Etherscan. It is Circle's USDC, 6 decimals, not Tether and not Maker DAI. A credit at any other dollar contract means you are looking at a different trade than this quote. Match the address before you treat the invoice as paid.

My Base balance is native ETH, not WETH. Can I use this page?

Not until you wrap. This route only sees WETH at the Base predeploy. Native ETH stays the gas coin until a wrap mints the ERC-20. If you wanted to sell the gas coin itself for USDC, choose the native ETH route instead of approving a token you do not hold.

Live execution

Trade on XAUConnect

Open the swap page with this cross-chain route pre-selected, then connect your wallet on the source chain to quote and execute. You keep the keys.

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