What Is ERC-721?
ERC-721 is the Ethereum token standard that defines non-fungible tokens (NFTs). Unlike fungible ERC-20 tokens, where every unit is identical, each ERC-721 token is unique and indivisible — it has its own distinct identity and cannot be swapped one-for-one with another.
This uniqueness makes ERC-721 the foundation for digital collectibles, art, in-game items, domain names, and proof of ownership of one-of-a-kind assets.
How Does ERC-721 Work?
Each token is assigned a unique token ID within its smart contract.
The contract tracks who owns each individual token ID.
Metadata (image, attributes, etc.) is linked to each token, often stored off-chain or on IPFS.
Ownership can be transferred, but each token remains distinct and indivisible.
Fungible vs Non-Fungible
| Feature | ERC-20 (Fungible) | ERC-721 (Non-Fungible) |
|---|---|---|
| Interchangeable | Yes — units are identical | No — each token is unique |
| Divisible | Yes (fractions) | No (whole tokens only) |
| Example | A dollar, a share | A specific piece of art |
| Use case | Currencies, utility tokens | Collectibles, art, IDs |
What Are ERC-721 Tokens Used For?
Digital art and collectibles — unique, verifiable ownership of artwork.
Gaming items — one-of-a-kind in-game assets owned by players.
Domain names — blockchain-based naming (e.g. ENS).
Membership and access — token-gated communities and events.
Real-world assets — representing ownership of unique items.
ERC-721 vs ERC-1155
ERC-721 handles one unique token per ID, while ERC-1155 is a multi-token standard that can manage both fungible and non-fungible tokens in a single contract — more efficient for projects (like games) that issue many item types. ERC-721 remains the classic, widely recognized NFT standard.
ERC-721 and Trust Wallet
Trust Wallet supports NFTs built on ERC-721, so you can store, view, send, and receive your collectibles and digital art directly in the app. As a non-custodial wallet spanning 100+ blockchains, your NFTs are secured by your own private keys — only you control your unique tokens, and you can manage them alongside your fungible assets in one place.
