WETH vs ETH explained: why the ERC-20 wrapper exists, how the 1:1 peg works, and exactly when DeFi and NFT users need wrapped Ether instead of native ETH.
When comparing WETH vs ETH, the key distinction is that wrapped ether adds the ERC-20 interface native ETH lacks, enabling seamless use across DeFi and NFT protocols.
ETH launched before the ERC-20 standard was finalized, so it never implemented the core interface functions that later protocols require. DEX routers, lending markets, liquidity pools, and NFT marketplaces all expect tokens to expose approve(), transferFrom(), and related methods so smart contracts can handle delegated transfers and conditional spending without constant user intervention.
Native ETH provides none of these. A protocol that wants to accept ETH directly must either build separate code paths for the native asset or force users to interact through workarounds that break composability. The result is duplicated logic, higher audit surface, and slower feature development across the ecosystem.
Gas fees remain payable only in native ETH regardless of which token is being transferred. Even after a user wraps ETH, every on-chain action—including the wrap or unwrap transaction itself—still consumes ETH for fees. Protocols therefore cannot treat WETH as a complete replacement; users must always maintain a small ETH balance to keep transactions moving.
Because ETH predates standardized token interfaces, the ecosystem converged on a minimal wrapper that adds ERC-20 compatibility while leaving the underlying economics and gas mechanics unchanged.
The canonical WETH9 contract at address 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 creates the peg through a deposit-and-mint flow. A user transfers ETH directly to the contract. The contract accepts the deposit, locks the ETH in its balance, and mints an exactly equal quantity of WETH tokens to the sender’s address. Every mint event is matched one-to-one with ETH held inside the contract.
Redemption works in the opposite direction. The holder calls the withdraw function and specifies an amount of WETH. The contract burns those tokens and releases the identical quantity of ETH back to the caller. Because the contract only releases ETH that it already holds, the 1:1 ratio is enforced by code rather than by external reserves or oracles.
The contract contains no owner address and no minting privileges beyond the deposit path. Since its 2017 deployment, only incoming ETH can trigger new WETH issuance. No administrative function exists to mint tokens without a corresponding deposit or to withdraw locked ETH without a matching burn. This minimal design keeps the peg mechanical and verifiable on-chain.
The core distinctions between native ETH and WETH appear most clearly when examined side by side across the dimensions that matter for DeFi usage.
| Attribute | Native ETH | WETH |
|---|---|---|
| ERC-20 interface support | No approve(), transferFrom() or other standard functions | Full ERC-20 compliance via the canonical contract |
| Use in liquidity pools | Not supported by most DEX routers and automated market makers | Primary pairing token in the majority of Ethereum liquidity pools |
| Gas payment capability | Required for all transaction fees | Cannot pay gas; users must hold separate ETH |
| Locked supply (late 2024) | — | 2.04–2.26 million WETH locked in the canonical contract (MetaMask, Blockchair and weth.io snapshots) |
| DeFi TVL contribution | Indirect through base-layer activity only | Directly powers over $150 billion in DeFi TVL (weth.io) |
These differences stem directly from ETH’s pre-ERC-20 origins. The roughly 2 million-plus WETH tokens currently locked represent between 1.9 % and 3 % of total ETH supply depending on the late 2024 source consulted. Because only native ETH can cover network fees, every WETH position still requires a small ETH reserve, creating a persistent operational split for users. The $150 billion TVL figure underscores how heavily lending markets, perpetual exchanges and NFT platforms now rely on the ERC-20 wrapper rather than raw ether.
DeFi protocols built on Ethereum expect the full ERC-20 interface that native ETH never received. Providing liquidity on Uniswap for an ETH pair therefore begins with wrapping. The pool contract and router rely on approve and transferFrom calls to move tokens into the position; native ETH triggers a revert because it lacks these functions. The same pattern appears when posting collateral on Aave. The lending market must lock the asset and update the user’s borrowing capacity through standard token methods, so users supply WETH rather than raw ETH to avoid transaction failure.
NFT marketplaces follow the identical requirement. On OpenSea, bid escrow contracts hold WETH until an auction settles or a buyer accepts an offer. The contract cannot escrow native ETH through the same approval flow, so active bidders keep the wrapped token ready. Assets that arrive from L2 bridges present another case. Bridge contracts on mainnet deliver WETH to preserve ERC-20 compatibility across chains; recipients receive the wrapped form and must unwrap only if they need native ETH for gas.
In each setting the limitation is technical rather than economic. The 1:1 peg keeps value identical, yet the interface mismatch forces the extra conversion step before the protocol can process the transaction.
Traders must retain a separate balance of native ETH at all times because gas fees on Ethereum are paid exclusively in the original asset. Running out of unwrapped ETH while holding only WETH halts further transactions until a swap or withdrawal occurs.
The canonical contract maintains a strict 1:1 redemption guarantee through its withdraw function, which burns WETH and releases the exact equivalent ETH on demand. No additional fees apply beyond ordinary gas costs, and the mechanism has operated without change since 2017.
Canonical WETH contracts appear on mainnet and major L2s at distinct addresses, yet bridged or variant tokens such as WETH.e on Avalanche remain separate assets that cannot be substituted. Attempting to use a bridged token inside a canonical liquidity pool typically results in failed approvals or lost liquidity.
Recent snapshots place roughly 2.04 million to 2.26 million WETH locked in the canonical contract, equal to between 1.9 % and 3 % of total ETH supply. This modest share indicates that the majority of ETH continues to circulate unwrapped, limiting systemic reliance on the wrapper while still powering substantial DeFi activity.
Wrapping requires a deposit transaction to the canonical contract that burns no ETH beyond the amount locked. You pay only the network gas fee in native ETH; no additional token fee or spread applies because the contract maintains a strict 1:1 peg.
No. Each Layer-2 network deploys its own canonical WETH contract at a distinct address. Bridged or variant tokens on those chains are not interchangeable with mainnet WETH.
Most exchanges accept WETH deposits provided the token matches the network they list. Always confirm the deposit address and chain before sending, because the exchange will credit WETH, not automatically convert it to ETH.
aWETH is Aave’s interest-bearing receipt token issued when you supply WETH to the protocol. It represents your deposit plus accrued interest and cannot be used directly in other DeFi contracts the way plain WETH can.
Unwrapping is unnecessary inside any protocol that already accepts WETH, such as DEX routers, lending markets, or NFT marketplaces. You only need native ETH to pay gas fees or to exit the ecosystem entirely.
Yes. Non-canonical wrappers, bridged tokens such as WETH.e, and interest-bearing variants like aWETH carry different contract addresses and redemption mechanics. Using the wrong token breaks compatibility with most DeFi applications.
