Cross-chain · Ethereum → Polygon

Swap WETH from Ethereum to USDT on Polygon

Swap WETH from Ethereum to USDT on Polygon. A chain 137 wallet that needs Tether spends wrapped ETH from Ethereum and receives the PoS USDT.

Approve WETH at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 on Etherscan. That contract is not native ETH. The Tether you receive is 0xc2132D05D31c914a87C6611C10748AEb04B58e8F on Polygonscan, 6 decimals. Ethereum USDT at 0xdAC17F958D2ee523a2206206994597C13D831ec7 is a different contract on Etherscan. Gas to start is ETH on chain id 1. Gas after arrival is POL on chain id 137. Switch to chain id 137 and match the Polygonscan USDT before you tell a payee the transfer finished. An Ethereum address will not display this balance.

Diagram for Swap WETH from Ethereum to USDT on Polygon
WETH leaves Ethereum. USDT is what can arrive on Polygon.

WETH on Etherscan, USDT on Polygonscan

The spend is 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2. The receipt is 0xc2132D05D31c914a87C6611C10748AEb04B58e8F. A wallet that labels both with familiar tickers can still be pointed at a copy. Etherscan and Polygonscan are the two checks. They are not two views of one token.

Sell WETH for USDT on mainnet if you are staying

This route is the wrong tool if you want Ethereum Tether or native ETH. Mainnet pools already pair WETH with USDT, and unwrapping WETH is a local withdraw. Use the bridge when the Tether contract you were given is the Polygon one. Staying on chain id 1 is simpler when the pool is already there.

POL comes second

Ethereum blocks are about 12 seconds and the fee is ETH, even though the token moving is WETH. Polygon blocks are about 2 seconds and the fee is POL. Polygon will not treat USDT as gas. Keep POL on the destination address or the Tether waits.

Payments that name this USDT

Send the output only to a chain 137 address that expects 0xc2132D05D31c914a87C6611C10748AEb04B58e8F. An Ethereum address controlled by the same person will not show the tokens on Etherscan. Tell the payee the network as well as the amount on the quote.

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 Ethereum to USDT on Polygon?

Approve WETH at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 on Etherscan. That contract is not native ETH.

Is spending WETH the same as spending ETH?

No. WETH is the ERC-20 at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2. Native ETH is the gas coin, marked 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE when a route needs it. This pair approves WETH. You still need a separate ETH balance for the chain id 1 fee. Unwrapping first stays on Ethereum.

Which USDT contract arrives on Polygon?

0xc2132D05D31c914a87C6611C10748AEb04B58e8F on Polygonscan, 6 decimals. Ethereum Tether at 0xdAC17F958D2ee523a2206206994597C13D831ec7 is not credited. If your payee uses the Ethereum contract, this route is the wrong tool. Match the address the invoice printed, then switch the wallet to chain id 137. Then switch the wallet to chain id 137.

What stops the USDT from moving later?

An empty POL balance. Chain id 137 charges POL for every token transfer. The USDT cannot sponsor itself. Put POL on the receiving wallet before a second transaction. Blocks are about 2 seconds after that fee can be paid. Blocks there are about 2 seconds after POL is in the wallet.

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.

Swap cross-chainExplore markets

Continue exploring

Related markets, guides & networks

Next pages on this subject. Read them before you trade.

Networks
Tokens
Guides
Articles

Build programmatically

Swap via API for bots and AI agents: quotes, builds, and cross-chain routes.

Developer quickstart