Ethereum token standards are the shared rulebooks that let tokens work everywhere — in wallets, on exchanges, and across DApps. Without them, every token would be a custom puzzle. The three standards you need to know are ERC-20 (fungible tokens), ERC-721 (NFTs), and ERC-1155 (multi-token). Here’s how each works and when developers choose one over the others.
What Is a Token Standard?
An ERC (Ethereum Request for Comments) standard defines a set of functions and behaviors a smart contract must implement — things like “how do I check a balance?” or “how do I transfer a token?” When every token contract answers those questions the same way, wallets like MetaMask and exchanges like Uniswap can support thousands of tokens without custom integration work. Standards are what make Ethereum’s token ecosystem composable.
ERC-20: The Fungible Token Standard
ERC-20 defines fungible tokens: every unit is identical and interchangeable, like dollars or shares of stock. One USDC is exactly like any other USDC.
Key ERC-20 functions include totalSupply, balanceOf, transfer, and approve/transferFrom (which let DApps move tokens on your behalf after you grant permission). ERC-20 powers:
- Stablecoins (USDC, USDT, DAI)
- Governance tokens (UNI, AAVE)
- Wrapped assets (WBTC)
- Liquid staking tokens (stETH)
Its simplicity is its strength — and its limitation: ERC-20 can’t represent unique items.
ERC-721: The NFT Standard
ERC-721 defines non-fungible tokens: each token has a unique ID and distinct properties. Your Bored Ape is not interchangeable with anyone else’s.
ERC-721 contracts track ownership per token ID and include metadata pointers (usually to IPFS or Arweave) describing the token’s image and traits. This standard ignited the NFT boom across digital art, collectibles, gaming items, event tickets, and domain names (ENS names are ERC-721 tokens).
The tradeoff: minting and transferring many individual ERC-721 tokens can be gas-intensive, since each token is managed separately.
ERC-1155: The Multi-Token Standard
ERC-1155, proposed by Enjin’s Witek Radomski, lets a single contract manage many token types — fungible, non-fungible, and semi-fungible alike. Think of it as a vending machine stocked with many products instead of one contract per product.
Advantages of ERC-1155:
- Efficiency: batch transfers move many token types in one transaction, saving significant gas.
- Flexibility: a game can issue both its currency (fungible) and its swords (unique) from one contract.
- Semi-fungible tokens: items like concert tickets that are identical until redeemed, then become unique.
The cost is complexity: ERC-1155 contracts are harder to write and audit, and tooling support historically lagged behind ERC-721.
ERC-20 vs ERC-721 vs ERC-1155: Side-by-Side Comparison
- Fungibility: ERC-20 (fungible only) · ERC-721 (non-fungible only) · ERC-1155 (both, plus semi-fungible)
- Contract structure: ERC-20 and ERC-721 typically use one contract per token collection; ERC-1155 handles unlimited token types in one contract
- Gas efficiency: ERC-1155 wins for bulk operations thanks to batch transfers
- Ecosystem support: ERC-20 and ERC-721 enjoy the widest wallet and marketplace support; ERC-1155 support is broad but slightly less universal
- Typical uses: ERC-20 for currencies and governance · ERC-721 for art, collectibles, identity · ERC-1155 for gaming and large-scale mints
Ethereum Token Standards: Which Should Developers Choose?
- Building a currency, stablecoin, or governance token? ERC-20.
- Minting unique collectibles or art where per-token identity matters? ERC-721.
- Running a game with thousands of item types, or doing large batch mints? ERC-1155.
Beyond the Big Three: Emerging Ethereum Token Standards
ERC-20, ERC-721, and ERC-1155 cover most needs, but newer standards solve specialized problems:
- ERC-4626 (tokenized vaults): a standard interface for yield-bearing vaults — deposit assets, receive vault shares. It made Yearn-style vaults composable, so other protocols can build on any compliant vault.
- ERC-4337 (account abstraction): not a token standard but a landmark one: it enables smart-contract wallets with programmable validation, letting wallets sponsor gas fees and batch transactions without protocol changes.
- Soulbound tokens (ERC-5192, ERC-5484): non-transferable tokens for credentials, memberships, and reputation that shouldn’t be sellable.
- ERC-2981 (royalty standard): a uniform way for NFT contracts to signal royalty info, though enforcement still depends on marketplaces.
The pattern is consistent: each new standard removes another integration headache, compounding Ethereum’s network effects. When evaluating a new standard, ask three questions: is it finalized or still draft? Do major wallets and marketplaces support it? And does it solve a problem you actually have? Adopting a draft standard early can mean painful migrations later. The big three earned their dominance through years of battle-testing — newcomers should clear a high bar before you build on them.
Security Notes for Token Users
Standards guarantee interface compatibility, not safety. Malicious actors deploy fake ERC-20 “lookalike” tokens with names mimicking real projects — always verify contract addresses from official sources. Unlimited token approvals to shady contracts are a classic drain vector, so revoke approvals you don’t need. Token prices are volatile and many tokens go to zero; this article is educational, not financial advice.
Together, these three Ethereum token standards form the vocabulary of on-chain value. New standards continue to emerge — for soulbound tokens, tokenized real-world assets, and more — but ERC-20, ERC-721, and ERC-1155 remain the foundation everything else builds on.
