Cross-chain · Base → Ethereum

Swap WETH from Base to USDT on Ethereum

Swap WETH from Base to USDT on Ethereum. You send Base WETH and you receive Tether USDT on Ethereum mainnet.

Confirm the source on Basescan: 0x4200000000000000000000000000000000000006, chain 8453, an L2 where gas is still ETH. Confirm the destination on Etherscan: 0xdAC17F958D2ee523a2206206994597C13D831ec7, chain 1, about 12 seconds a block. That contract is Tether, 6 decimals. It is not Circle USDC at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 and it is not canonical WETH at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2. The placeholder 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE means native gas, which you are not delivering.

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

Tether is the point of the trade

People pick this route when a venue, a market, or a payment rail settles in Tether rather than Circle. The price can look identical and the contract still be wrong. Tether also operates a freeze list. If an address is blocked, holding the right contract does not make the balance useful. That is a property of this token, not a reason to accept a lookalike USDT from a different deployer.

What the allowance is allowing

You are allowing a router to move Base WETH, not to move Ethereum USDT in advance. The USDT does not exist in your wallet yet. After the hop, a later Ethereum app may ask for a second approval, and that one is paid with mainnet ETH. Mixing those two requests up is how people approve the wrong chain. This page does not ask you to approve USDT in order to receive it.

Wrong job, listed without decoration

Wrong if you need Circle's redemption contract. Wrong if you need DAI from Maker, which has 18 decimals and a different issuer. Wrong if the input is native ETH and you have not wrapped. Wrong if you wanted Ethereum WETH so a pool can pair it. Wrong if both sides of the deal are already on Base. The bridge is justified when the Tether balance must sit on Ethereum.

Two explorers, no shared clock

Basescan shows WETH leaving. Etherscan shows USDT arriving. How cross-chain bridges work is the reason those pages do not share a transaction hash. Block time on Ethereum is about 12 seconds. The bridge adds its own wait, and that wait is not stated as a duration here. Refresh the quote if it expires. Do not sign a minimum you would not accept.

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 USDT on Ethereum?

Confirm the source on Basescan: 0x4200000000000000000000000000000000000006, chain 8453, an L2 where gas is still ETH. Confirm the destination on Etherscan: 0xdAC17F958D2ee523a2206206994597C13D831ec7, chain 1, about 12 seconds a block.

Will this USDT be frozen just because it crossed from Base?

Crossing does not by itself freeze a balance. Tether can still freeze addresses under its own rules, on the contract 0xdAC17F958D2ee523a2206206994597C13D831ec7. If your address is already listed, do not expect this route to produce a spendable balance. Circle USDC is a different issuer and a different contract if your policy cannot use Tether.

Do I approve USDT on Ethereum before it arrives?

No. You approve Base WETH at 0x4200000000000000000000000000000000000006 so the router can take the input. USDT is the output. An approval of USDT would only matter later, if an Ethereum app needs to pull those tokens, and that signature would be on chain 1, paid in ETH.

Is Base WETH the same contract as Ethereum WETH?

No. Base uses 0x4200000000000000000000000000000000000006. Ethereum canonical WETH is 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2. This route spends the Base contract and does not deliver the Ethereum one. It delivers Tether USDT, which you verify on Etherscan. ETH and WETH remain different assets on both chains, and this quote buys neither of them on mainnet.

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