If you’ve used a cryptocurrency or digital collectible on Ethereum, you’ve interacted with a token standard—probably without realizing it. These standards are the technical backbone that determines how tokens behave, transfer, and hold value on the blockchain. Understanding the differences between ERC-20, ERC-721, and ERC-1155 matters for anyone evaluating tokens, building Web3 projects, or trying to make sense of the NFT versus utility token debate.
Each standard serves a fundamentally different purpose, and picking the wrong one has real consequences. I’ve seen projects waste months of development time because they chose ERC-721 for something that should have been ERC-20, or built on ERC-1155 when a simpler standard would have worked fine. Let me break down what each one does, where it excels, and which tokens you already know use them.
What is ERC-20?
ERC-20 came out in 2015 as Ethereum’s first standardized approach for fungible tokens—assets where every unit is identical and interchangeable. Think of it like cash: a $10 bill is worth exactly the same as any other $10 bill, and they swap freely without any difference in value.
The standard defines six functions that every ERC-20 token must implement: totalSupply, balanceOf, transfer, transferFrom, approve, and allowance. This consistency is what makes ERC-20 tokens work across Ethereum wallets, exchanges, and smart contracts. Before this standardization, integrating new tokens was a fragmented nightmare—every token required custom integration work.
Most cryptocurrencies built on Ethereum use ERC-20. Chainlink (LINK), Uniswap (UNI), and USD Coin (USDC) are all ERC-20 tokens. This standard works well for utility tokens representing voting rights, access privileges, or value within a specific ecosystem. It’s also the standard behind most initial coin offerings and DeFi applications.
One limitation: ERC-20 tokens can’t represent unique items. You can’t create one-of-a-kind collectibles or track individual ownership history with this standard alone. That’s where ERC-721 comes in.
What is ERC-721?
ERC-721 brought non-fungible tokens (NFTs) to Ethereum in 2017, and it changed how we think about digital ownership. Unlike ERC-20, where every token is identical, ERC-721 gives each unit a unique tokenId. No two ERC-721 tokens are alike—each one is distinct and can be individually traced.
The standard requires implementing ownerOf (to see which address owns a specific tokenId), transferFrom (to move a specific token), and other functions that track individual token histories. Every Axie Infinity character, every Bored Ape, and every piece of digital art on OpenSea uses ERC-721.
What makes ERC-721 powerful is its ability to represent true ownership. A token isn’t just a balance in a wallet—it’s a specific, verifiable claim to something unique. This opened the door for gaming assets, digital art, domain names, and identity credentials. When you “own” an NFT, the blockchain records exactly which tokenId you hold, and that record can’t be forged or duplicated.
The standard has drawbacks, though. Each token needs its own storage and tracking, which means higher gas fees for minting and transferring compared to ERC-20. If you wanted to create 10,000 identical game items, ERC-721 would be inefficient—you’d need 10,000 individual tokens or workarounds. That’s the problem ERC-1155 was designed to solve.
What is ERC-1155?
ERC-1155 came out in 2019 as a multi-token standard that combines the best of both worlds. Developed by Enjin, a blockchain gaming company, it lets a single smart contract manage unlimited quantities of both fungible and non-fungible tokens. This is a big architectural improvement over the binary choice ERC-20 and ERC-721 previously offered.
In practical terms, a game developer could use ERC-1155 to create a single contract handling gold coins (fungible), unique weapons (non-fungible), and limited-edition potions (semi-fungible—limited quantity but identical within that quantity). Previously, this would have required multiple separate token contracts, each with its own overhead and gas costs.
The efficiency gains are significant. ERC-1155 supports batch transfers, meaning you can move multiple token types in one transaction. This reduces gas costs significantly—Enjin has shown savings up to 90% compared to managing separate ERC-20 and ERC-721 contracts for equivalent functionality.
Games like Gods Unchained and platforms like OpenSea have adopted ERC-1155 for its flexibility. However, it hasn’t replaced ERC-20 or ERC-721—each standard still dominates its specific use case. ERC-1155 shines when you need both token types in one ecosystem, but it adds complexity that simpler projects may not need.
ERC-20 vs ERC-721 vs ERC-1155: A Direct Comparison
The differences become clearer when placed side by side:
| Attribute | ERC-20 | ERC-721 | ERC-1155 |
|---|---|---|---|
| Token Type | Fungible (identical) | Non-fungible (unique) | Both |
| Use Case | Currencies, utility tokens | Digital art, collectibles, gaming | Gaming items, mixed assets |
| Token ID | No unique ID per unit | Unique ID per token | Multiple IDs allowed |
| Interoperability | High (widely supported) | High (NFT ecosystem) | Growing |
| Gas Efficiency | High | Lower for single items | Highest for mixed batches |
| Examples | USDC, UNI, LINK | CryptoPunks, Bored Apes | Gods Unchained cards, ENS domains |
The core distinction comes down to fungibility. ERC-20 tokens are interchangeable—your UNI is identical to mine. ERC-721 tokens aren’t—each CryptoPunk has its own identity and value. ERC-1155 handles both, giving developers flexibility but at the cost of additional implementation complexity.
Which Token Standard Should You Use?
The answer depends entirely on what you’re building.
Use ERC-20 if you’re creating a cryptocurrency, utility token, governance token, or any asset where individual units don’t need to be distinguished from each other. This standard integrates with every major exchange and DeFi protocol. If your token represents “value” in a general sense, ERC-20 is probably right.
Use ERC-721 if you’re building something where each unit must be individually identifiable and verifiably unique. This applies to digital art marketplaces, domain name systems, identity credentials, and gaming assets where rarity and uniqueness drive value. The NFT ecosystem around ERC-721 is mature, with established marketplaces and wallet support.
Use ERC-1155 if your project spans both token types or if you’re building a gaming ecosystem where efficiency matters. The ability to mint thousands of fungible game items while also supporting unique collectibles in one contract makes this the standard of choice for complex gaming applications.
A common mistake I see is projects choosing ERC-721 for fungible assets “because NFTs are popular.” That’s a decision that will cost you significantly more in gas fees and limit your DeFi integrations. Conversely, building a collectibles project on ERC-20 means you can’t prove ownership of a specific item—which defeats the entire purpose.
Frequently Asked Questions
Can a single smart contract implement multiple ERC standards?
Yes, but it’s not straightforward. A contract can implement multiple interfaces, but mixing ERC-20 and ERC-721 logic in one contract requires careful design. ERC-1155 was specifically created to avoid this complexity by handling both token types natively.
Are ERC-20 tokens also NFTs?
No. By definition, ERC-20 tokens are fungible—every unit is identical. NFTs require a unique identifier per token, which ERC-20 doesn’t support. Some projects have tried “fractional NFTs” by issuing ERC-20 tokens representing shares of a single NFT, but that’s different from the underlying standard.
Which standard is most widely used?
ERC-20 dominates in terms of total value and adoption—most cryptocurrencies and DeFi tokens use it. ERC-721 leads in the NFT space. ERC-1155 is growing in gaming but hasn’t matched the ecosystem maturity of the other two.
Do these standards only work on Ethereum?
The ERC standards are specific to Ethereum, but other blockchains have adopted compatible or similar standards. Polygon, Avalanche, and BNB Smart Chain support ERC-20 and ERC-721 natively. Some chains use their own equivalents—Solana uses SPL tokens, and Binance has BEP-20—which function similarly but aren’t directly compatible.
The Bottom Line
ERC-20, ERC-721, and ERC-1155 aren’t competing standards—they’re tools designed for different jobs. Understanding what each one does well isn’t just technical trivia; it directly impacts how you evaluate tokens, build applications, and think about digital ownership.
The space keeps evolving. ERC-6551 (token-bound accounts) is pushing NFT functionality further, and new standards will emerge as use cases develop. But for now, these three cover the vast majority of what’s happening on Ethereum—and understanding them gives you a foundation for everything else that follows.
