Swap WETH at the Best Rate

What is WETH?

WETH is not a separate asset with its own market. It is a receipt for ether locked in a contract, and it is worth one ETH because anyone can redeem it for one ETH at any time. On Ethereum the canonical wrapper is the WETH9 contract at 0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2, deployed in 2017.

The reason it exists is a sequencing accident. Ether shipped before ERC-20 was written, so ETH has no transfer, approve or allowance interface. Pools, lending markets and order books are built against that interface, so they hold WETH and unwrap only at the edges.

How WETH works

The contract has two functions that matter. Sending ETH to deposit mints an equal amount of WETH to the sender; calling withdraw burns WETH and pays back the same amount of ETH. There is no oracle, no reserve ratio and no counterparty setting a rate: the balance sheet is the ETH sitting in the contract.

Wrapping is a transaction, so it costs gas and you still need native ETH to pay for it. Many interfaces wrap and unwrap for you inside a swap, which is why a trade quoted in ETH can settle against a WETH pool without you handling WETH yourself.

WETH supply and tokenomics

WETH has no issuance schedule, no cap and no team allocation. Supply is whatever is currently deposited: every unit is minted by a deposit and destroyed by a withdrawal, so the total tracks how much ether the ecosystem is holding in ERC-20 form at that moment. Nothing dilutes existing holders, because nothing can be minted without matching ETH.

Who builds WETH

There is no company behind WETH and no treasury. The wrapper pattern came out of the early Ethereum developer community, the canonical contract is open source, and it has no owner, no admin key and no upgrade path. Documentation lives on ethereum.org rather than a project site.

That immutability is the point. The contract has held large balances since 2017 without being exploited, and it has been formally verified, the strongest assurance level applied to Ethereum contracts.

How WETH is governed

None. WETH9 has no governance token, no proposals and no privileged role that could pause it, change its logic or seize a balance. Any change would mean deploying a different contract and persuading the ecosystem to migrate, which is why the 2017 deployment is still the one in use.

What people use WETH for

Almost every ETH-denominated position in decentralized finance is really a WETH position under the hood, because the contracts holding it can only speak the ERC-20 interface.

• Trading pairs: WETH is the base asset in most Ethereum pools, including WETH to USDC and WETH to USDT.
• Liquidity provision, where a pool needs two ERC-20 tokens.
• Collateral in lending markets that only accept standard tokens.
• Order-book protocols and NFT marketplaces that settle in an ERC-20 asset.

WETH risks and considerations

The wrapper itself is about as simple as an Ethereum contract gets, so the practical risks sit around it. Wrapping and unwrapping cost gas, and running your balance down to zero ETH leaves you unable to unwrap.

The bigger hazard is impostors. Tokens called WETH exist on many networks: some are canonical wrappers deployed by that chain, others are bridged representations whose backing depends on the bridge, and receipt tokens such as aWETH represent a lending position rather than ether. Check the contract address for the network you are on before swapping.