Cross-chain · Arbitrum One → Base

Swap USDT from Arbitrum One to WETH on Base

Swap USDT from Arbitrum One to WETH on Base. Tether USDT leaves Arbitrum One and Base WETH arrives on Base.

Spend Tether at 0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9. Arbiscan, chain id 42161, not Nova. Fee in ETH. Receive 0x4200000000000000000000000000000000000006 on Base. Basescan should show that predeploy. It is not native ETH and not 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2. Chain id 8453 is an L2. Blocks are about 2 seconds. Do not use the block time as a fill promise.

Diagram for Swap USDT from Arbitrum One to WETH on Base — USDT leaves Arbitrum One. WETH is what can arrive on Base.

Predeploy versus the sentinel

Base pools that say ETH often mean 0x4200000000000000000000000000000000000006. The wallet's gas row is the sentinel instead. This route can credit the predeploy. It will not increase the gas row. If you import Ethereum's WETH address on Base, you will be watching an empty, wrong contract. The reused 0x4200 hex on another OP-stack chain is also not this balance.

You may be unable to touch what you receive

Moving WETH costs native ETH on Base. A brand new Base account with only this credit cannot unwrap and cannot transfer. Plan a little Base ETH from somewhere else, or pick the native ETH output if gas was the real goal. Tether on the source still needs Arbitrum ETH before any of that matters.

Issuer and exposure both change

Tether is a dollar token. WETH is ether exposure. The minimum is a price. It expires. Six decimals versus eighteen. Base is the destination L2, chain id 8453. Etherscan will not list this WETH balance. If you open the wrong explorer, you will think the route failed when it landed on Base.

Wrong for USDC, for gas, and for mainnet

Circle USDC at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 is a different output. Native ETH is a different output. Ethereum mainnet is a different chain. Nova is the wrong source. Selling Arbitrum WETH is a different input. This page spends Tether only. Before you sign, compare 0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9 with 0x4200000000000000000000000000000000000006 on their explorers and stop if either address on the quote differs. Do not treat a block interval on either chain as a promise for when the credit appears. Gas on the source chain is separate from the asset you hope to receive.

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 USDT from Arbitrum One to WETH on Base?

Spend Tether at 0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9. Arbiscan, chain id 42161, not Nova. XAUConnect compares live routes and lets your own wallet sign.

What is the WETH address on Base?

0x4200000000000000000000000000000000000006. Confirm it on Basescan, chain id 8453. It is not Ethereum WETH at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 and not native ETH. You spend Tether at 0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9 on Arbitrum One. The same 0x4200 hex on another rollup is not your Base balance. Confirm that address on the explorer before you sign, and refresh the quote if it has expired.

Will this WETH pay Base gas?

No. Gas is native ETH, sentinel 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE on chain id 8453. WETH is an ERC-20. If the Base account has no ETH, you cannot unwrap. About 2 seconds is a block interval, not a gas balance. You also need ETH on Arbitrum One, chain id 42161, to move the USDT.

Is USDT on Base the thing I receive?

No. The output is WETH. If you wanted Circle USDC on Base, the contract would be 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, and this page does not name it. Starting with Tether does not mean the ticker survives. Read the receive address on the quote before you sign. Confirm the address on the explorer before you sign.

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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