Cross-chain · Base → Avalanche C-Chain

Swap WETH from Base to AVAX on Avalanche C-Chain

Swap WETH from Base to AVAX on Avalanche C-Chain. Base WETH leaves, and native AVAX arrives on the C-Chain, chain 43114.

You approve 0x4200000000000000000000000000000000000006 on Base, chain 8453. Basescan shows the ERC-20. The approval costs ETH. You receive native AVAX, written as 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE. Snowtrace shows it on the C-Chain account, not as a token. Unwrapping on Base would have returned ETH on Base, which cannot pay Avalanche fees. This is not the X-Chain. Tether and Circle USDC are different outputs.

Diagram for Swap WETH from Base to AVAX on Avalanche C-Chain
WETH leaves Base. AVAX is what can arrive on Avalanche C-Chain.

Wrapper in, fee coin out

You give up an ERC-20 claim on ETH and receive the coin that pays C-Chain fees. The quote sets the amount. It is not sized as a reserve for later transactions. A small fill can be consumed quickly. Read the minimum before you treat the result as a funded gas tank.

The Base approval still needs ETH

WETH cannot pay the allowance fee until it is unwrapped, and unwrapping would take you off this route. Keep a little ETH on chain 8453. AVAX is not on Base yet, so it cannot help. If you decline the spender, the router cannot pull the wrapper.

Not an unwrap, not a dollar, not the X-Chain

A local unwrap credits ETH on Base. A dollar route credits 0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E or 0x9702230a8ea53601f5cd2dc00fdbc13d4df4a8c7. An X-Chain address will not show this native C-Chain balance. WBTC is not part of the trade and is not native bitcoin. How to bridge assets between chains is the signing path, not a timer.

What success looks like

WETH down on Basescan. AVAX up on the Snowtrace account for chain 43114. No token contract page for the arrival. If you see a USDT transfer, you signed a different quote. No bridge duration is stated here. The C-Chain id is 43114, and an X-Chain balance is not a substitute for the AVAX this quote buys.

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 AVAX on Avalanche C-Chain?

You approve 0x4200000000000000000000000000000000000006 on Base, chain 8453. Basescan shows the ERC-20. XAUConnect compares live routes and lets your own wallet sign.

Is the AVAX I receive an ERC-20?

No. It is the native gas coin on the C-Chain, chain 43114. Quotes label it 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, and Snowtrace shows the account. The X-Chain is a different system. If a dapp asked for a token contract rather than the gas coin, this route did not provide that contract.

Can I unwrap Base WETH instead?

Yes, and the ETH stays on Base, chain 8453. Unwrapping burns 0x4200000000000000000000000000000000000006 locally. This page sends that wrapper toward the C-Chain and credits AVAX. Use the unwrap only when you intend to stay on Base and pay Base fees. This hop exists only when the AVAX must sit on the C-Chain.

What pays for the WETH approval?

ETH on Base. The wrapper is the token being approved, not the coin that pays gas. AVAX cannot cover that fee because it is not on chain 8453 yet. Keep a little ETH beside the WETH or the allowance cannot be mined. AVAX arrives later and cannot pay this Base fee.

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