Cross-chain · Base → Polygon

Swap USDC from Base to WETH on Polygon

Swap USDC from Base to WETH on Polygon. Circle USDC leaves Base, and Polygon WETH is what arrives on chain 137.

The USDC is Circle's Base contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, 6 decimals, on Basescan. Base is chain 8453 and the fee is ETH. The WETH is 0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619 on Polygon, chain 137, on Polygonscan. That is wrapped ether, an ERC-20. It is not POL, and it is not the Base WETH predeploy at 0x4200000000000000000000000000000000000006. Native gas on Polygon is 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, meaning POL. This route does not buy POL.

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

Polygon WETH is not the gas coin

Applications on Polygon use 0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619 when they want ETH exposure inside a token interface. The chain itself is paid in POL. A wallet full of this WETH and empty of POL cannot approve or transfer the WETH. Plan the fee coin separately. Native ETH on Ethereum is yet another balance, on chain 1, and it is not credited here.

You are leaving a dollar for wrapped ether

Circle USDC is a fiat-issued stable. WETH tracks ETH. This is not a dollar-to-dollar hop, and it is not a wrap of ETH you already hold. If you wanted Tether, the Polygon contract is 0xc2132D05D31c914a87C6611C10748AEb04B58e8F. If you wanted to keep USDC, do not sign. Price movement in ETH can dominate the result. Read the minimum WETH.

The Base predeploy will not satisfy Polygon

Holding or wrapping into 0x4200000000000000000000000000000000000006 keeps you on Base. Polygon pools will not see that contract. Canonical Ethereum WETH at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 is a third deployment. Match 0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619 on Polygonscan or you are inspecting the wrong chain.

Where the hop is unnecessary

If the Polygon position was not required, sell USDC for ETH on Base and stop. If the position was required, follow how cross-chain bridges work and still verify both addresses yourself. USDC needs an allowance on Base. WETH on Polygon will need POL before it can move. No bridge duration is promised.

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 Base to WETH on Polygon?

The USDC is Circle's Base contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, 6 decimals, on Basescan. Base is chain 8453 and the fee is ETH.

Can Polygon WETH pay the next fee?

No. WETH at 0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619 is an ERC-20. Gas on chain 137 is POL, the native coin, marked 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE in quotes. You need POL already on the account. ETH spent on Base does not become that POL. A WETH balance on Polygonscan is not a POL balance, and the wallet will not substitute one for the other.

Is this the same WETH contract as on Base?

No. Base WETH is 0x4200000000000000000000000000000000000006 on chain 8453. This route spends Circle USDC, not that WETH, and it delivers 0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619, which you check on Polygonscan. The tickers match. The chains and the contracts do not. Approving Base WETH would be a different route that does not start from USDC.

What if the app wanted POL instead of WETH?

Then this route is wrong. POL is the gas coin, not an ERC-20 you receive here. Choose the quote that delivers native POL. Staying in USDC, or switching only as far as Tether, is also a different page. Do not sign a WETH minimum if the order was a fee top-up.

Live execution

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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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