Cross-chain · Arbitrum One → Base

Swap WETH from Arbitrum One to ETH on Base

Swap WETH from Arbitrum One to ETH on Base. Arbitrum WETH leaves the wallet and native ETH arrives on Base.

Sell 0x82aF49447D8a07e3bd95BD0d56f35241523fBab1 on Arbitrum One. Arbiscan, chain id 42161, not Nova. The fee is native ETH on that same chain, a different row. Receive native ETH on Base, sentinel 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, chain id 8453. Basescan shows a balance, not the predeploy 0x4200000000000000000000000000000000000006. Base is an L2. Blocks about 2 seconds. Unwrapping on Arbitrum does not produce this balance.

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

Unwrap and bridge are different buttons

Withdraw on Arbitrum WETH returns ETH on chain id 42161. You stay home. This page can credit ETH on Base instead. The sentinel hex is on both sides of the quote and means a different chain's gas each time. Source sentinel: fee, not the sold token. Destination sentinel: the coin you can receive. If you wanted the predeploy, the gas coin is the wrong shape.

Useful when Base cannot sign

A Base account with tokens and no ETH is stuck. Native ETH fixes that. WETH at 0x4200000000000000000000000000000000000006 would not. Do not confuse the two after the credit lands. Basescan's balance, not a token page, is the check. Mainnet ETH will not appear. Chain id 1 is not involved.

Keep a little source ETH beside the WETH

The approval of 0x82aF49447D8a07e3bd95BD0d56f35241523fBab1 costs ETH on Arbitrum One. If you unwrap all WETH first, you no longer hold the contract this route spends, and you should switch to the native ETH route instead. Base is only the destination. The signature still happens on chain id 42161.

Wrong for the predeploy and for dollars

Stop if a pool wants 0x4200000000000000000000000000000000000006. Stop if you wanted Circle USDC. Stop if you are holding native ETH rather than WETH. Stop on Nova. Stop if you thought Arbitrum ETH and Base ETH were already the same object and this page was only a label change.

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 Arbitrum One to ETH on Base?

Sell 0x82aF49447D8a07e3bd95BD0d56f35241523fBab1 on Arbitrum One. Arbiscan, chain id 42161, not Nova. XAUConnect compares live routes and lets your own wallet sign.

Do I receive Base WETH or Base ETH?

Native ETH. The output marker is 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE on chain id 8453. The WETH predeploy is 0x4200000000000000000000000000000000000006 and is not the credit. You spend 0x82aF49447D8a07e3bd95BD0d56f35241523fBab1. Check the Base balance on Basescan. It can pay gas. The predeploy cannot. Confirm that address on the explorer before you sign, and refresh the quote if it has expired.

Will unwrapping Arbitrum WETH put ETH on Base?

No. It returns ETH on Arbitrum One only. This route is the one that can credit Base. If you already unwrapped, use the native ETH input route and reserve a fee. About 2 seconds is a Base block, not the unwrap, and not a promise. Nova is neither side.

Why does the sentinel appear twice?

It means native gas on each chain. On Arbitrum One it is the ETH you use as a fee while selling WETH. On Base it is the ETH you can receive. Same hex, chain id 42161 versus 8453. It is not Ethereum mainnet in either field. Etherscan is the wrong explorer for the credit.

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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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