Wrap WETH

WETH is Ether in ERC-20 form. ETH is Ethereum's native currency and predates the token standard, so it doesn't expose the transfer, balance, and approval functions most smart contracts expect. The ERC-20 token standard defines the common interface for balances, transfers, approvals, and delegated transfers. The wrapper contract fixes that: it holds your ETH and credits you an equal WETH balance that is transferable, approvable, and usable in delegated transfers.

Every WETH is backed by ETH sitting in the wrapper contract, and you redeem through the same contract at par. It is not a staking derivative like stETH or an interest-bearing receipt. Wrapping does not move value between networks: it is the same asset on the same chain with a different interface.

Wrapping takes one transaction, and unwrapping takes one transaction. Connect a self-custodial wallet, confirm you are on the intended network, and use the WETH contract for that network. On Ethereum mainnet (chain ID 1), the canonical WETH9 contract is 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2.

To wrap, send ETH to the contract's payable deposit() function. When the transaction confirms, the contract credits your wallet an equal WETH balance. There is no conversion fee and no slippage; the transaction uses network gas paid in native ETH.

To unwrap, call withdraw(amount) on the same contract. It burns that WETH balance and returns the identical amount of native ETH. One transaction each way completes when the transaction confirms, and timing depends on congestion and your gas settings.

Swap WETH like any other ERC-20 token, with an approval followed by the trade. Unlike a direct wrap, the route has a pool fee and price impact, and the DEX needs permission to move your WETH. The approval is a separate transaction that gives the router a token spending allowance; the swap can use only the amount covered by that allowance.

Before confirming the swap, compare the quoted minimum received, your slippage setting, and the price impact for your trade size. Many DEX interfaces also wrap ETH inline as part of the trade. That is the same deposit() mechanism bundled into the route.

WETH and ETH have the same value but different capabilities. ETH is the native asset: it pays gas, it is what the wrapper returns on withdrawal, and most wallets show it as the base balance. WETH is the ERC-20 representation: it works with approvals, allowances, and contracts written to the token standard, but it cannot pay gas.

Hold ETH for spending and gas; hold WETH while a contract or pool needs the ERC-20 form. Redemption is always 1:1, with no yield or penalty for either form. The choice changes the interface, not the economics.

Direct wrapping and unwrapping cost only network gas. The canonical wrapper charges nothing: there is no protocol conversion fee and no slippage. You put in 1 ETH and get 1 WETH, and vice versa. The deposit or withdrawal transaction uses Ethereum network gas paid in native ETH.

A DEX swap has different costs. It uses network gas, charges the pool's fee, and can add price impact when the trade is large relative to pool depth. Those costs belong to the exchange route, not WETH; the wrapper remains the fee-free path between ETH and WETH.

The canonical mainnet WETH9 contract has a narrow trust surface, but using WETH is not risk-free. The contract has no owner, no administrator, no proxy, and no privileged minting function. It can issue WETH only against ETH actually deposited. Its open-source code has been formally verified for important accounting and solvency properties. You can inspect the verified code and balances directly on the WETH contract page.

The main exposure is at the edges: fake wrapper contracts on other networks, phishing sites, approvals granted to malicious routers, and transactions sent on the wrong chain. Open-source and verified describes the canonical contract, not a lookalike reached through a bad link. Verify the network and contract address every time, and limit a router's allowance to the amount the trade requires instead of granting an unlimited approval.

A zero balance usually means the wallet is showing the wrong network or has not added that network's WETH contract. WETH contracts are per-chain. Switch to the network where you wrapped, then add the correct token contract so the balance displays. On Ethereum mainnet, the token address is 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2.

An unwrap fails or cannot be submitted when the wallet lacks native ETH for gas. If you wrapped the entire balance, send a small amount of ETH to the wallet first. A swap fails at the trade step when the approval is unconfirmed or the allowance is below the trade size. Confirm the approval and compare its allowance with the amount being swapped. WETH sent to an exchange as “ETH” requires the recipient's support. ETH and WETH are operationally different assets, and recovery may not be available.