A standard for non-fungible tokens (NFTs) on Ethereum.
ERC-721 is the Ethereum token standard used for non-fungible tokens (NFTs) — unique digital assets that cannot be exchanged one-to-one like fungible tokens. Each ERC-721 token has its own identifier, metadata, and characteristics, enabling digital ownership of items such as art, collectibles, in-game assets, and real-world tokenized goods.
What Makes ERC-721 Tokens Unique
The defining feature of ERC-721 tokens is non-fungibility:
Each token has a unique ID
No two tokens are identical
Ownership is individually tracked
Tokens can represent digital or physical uniqueness
This structure makes ERC-721 ideal for authenticating ownership and scarcity.
Key Functions of ERC-721
The standard includes methods such as:
ownerOf: Shows who owns a token
safeTransferFrom: Securely sends NFTs between wallets
tokenURI: Retrieves metadata (image, attributes, traits)
approve / setApprovalForAll: Enables marketplaces to manage transfers
These features ensure consistent NFT behavior across platforms.
Use Cases for ERC-721
Digital art
Collectibles and rare assets
Gaming items and avatars
Tokenized real estate
Domain names (ENS)
Membership passes and tickets
ERC-721 enabled the NFT boom by providing a reliable framework for uniqueness and ownership.
Benefits of ERC-721
Verifiable digital ownership
Secure and transparent provenance
Interoperability with NFT marketplaces
Flexibility for metadata and traits
Strong community and developer adoption
Summary
ERC-721 is the Ethereum standard for non-fungible tokens, powering NFTs and enabling verifiable ownership of unique digital and real-world assets.
