Ethereum Token Standards
ERC (Ethereum Request for Comment) standards define standard interfaces for smart contracts on Ethereum. Any token contract implementing the standard can interoperate automatically with all wallets, DEXs, and DeFi protocols — without custom integration.
ERC-20 — Fungible Tokens
Proposed: Fabian Vogelsteller, November 2015 Purpose: Tokens where each unit is identical and interchangeable (like currency)
Six mandatory functions:
totalSupply() — total token supply
balanceOf(address) — balance of an account
transfer(to, value) — send tokens
transferFrom(from, to, value) — spend pre-approved tokens
approve(spender, value) — authorise a spender
allowance(owner, spender) — query spending approval
Ecosystem: Hundreds of thousands deployed; ~15,000 actively traded. Powers stablecoins (USDT, USDC), governance tokens (UNI, AAVE, MKR), oracle tokens (LINK), meme coins (SHIB), and liquid staking tokens (stETH, rETH).
ERC-721 — Non-Fungible Tokens (NFTs)
Proposed: William Entriken et al., January 2018 Purpose: Unique tokens — each has a distinct ID, owner, and metadata URI
Each token:
- Has a unique integer ID within its contract
- Has exactly one owner at any time
- Can be transferred via
transferFromorsafeTransferFrom - Points to metadata (image, attributes) via a
tokenURI
Notable collections: CryptoPunks (Larva Labs, 2017), Bored Ape Yacht Club (Yuga Labs), Azuki, Pudgy Penguins. Cultural peak: Beeple’s “Everydays” sold for $69.3M at Christie’s (2021). First NFT project: Etheria (October 2015) — deployed at Ethereum’s first developer conference.
See also: nft
ERC-1155 — Multi-Token Standard
Purpose: Single contract manages both fungible and non-fungible tokens simultaneously
- Each token type has an integer ID
- Quantities >1 = fungible units of that type; quantity 1 with unique ID = non-fungible
- More gas-efficient than deploying separate ERC-20/ERC-721 contracts
- Enables batch transfers
Primary use case: Blockchain gaming — gold coins (fungible) and unique equipment items (non-fungible) in one contract. Used by Enjin, OpenSea shared storefront.
ERC-4626 — Tokenised Vault Standard
Purpose: Standardises yield-bearing token vaults in DeFi
When you deposit into a DeFi lending protocol, you receive a receipt token representing your share of the vault. ERC-4626 standardises how this receipt token works — enabling yield aggregators and portfolio protocols to interact with any compliant vault without custom code.
Used by: Yearn Finance, Aave, Compound, MorphoBlue.
Token Categories on Ethereum
| Category | Examples | Standard |
|---|---|---|
| Stablecoins | USDT, USDC, DAI | ERC-20 |
| DeFi governance | UNI, AAVE, MKR, CRV | ERC-20 |
| Liquid staking | stETH, rETH, cbETH | ERC-20 |
| Wrapped assets | WBTC, WETH | ERC-20 |
| NFT art/collectibles | BAYC, CryptoPunks | ERC-721 |
| Gaming items | Enjin assets | ERC-1155 |
| DeFi vault shares | Yearn yTokens | ERC-4626 |
Ecosystem Scale (2024–2025)
| Metric | Value |
|---|---|
| Total ERC-20 tokens deployed | ~500,000+ |
| Active ERC-20 tokens (traded) | ~15,000 |
| Stablecoin supply on Ethereum | ~$150B+ |
| DeFi TVL (Ethereum) | ~$60B+ |
| NFT collections (ERC-721) | ~100,000+ |
Sources: cryptoslate-2025-ethereum-tokens | wikipedia-2026-ethereum