Non-fungible tokens are built on two primary Ethereum standards: ERC-721 and ERC-1155. Each standard defines how unique or semi-fungible digital assets are created, transferred, and tracked on-chain. Choosing the right standard depends on your use case, gas budget, and the complexity of your token ecosystem. Here is a technical comparison to help you make the right decision.
ERC-721: The Original NFT Standard
ERC-721 defines a contract where each token has a unique ID and a single owner. It provides functions for transferring ownership, approving operators, and querying token ownership. Every token is distinct — there is no concept of quantity or fungibility within the contract. This makes ERC-721 ideal for one-of-a-kind digital assets like art, domain names, real estate deeds, and unique collectibles. The standard is widely supported by marketplaces, wallets, and indexers. However, each transfer is a separate transaction, making bulk operations expensive. Minting 100 NFTs requires 100 separate mint calls, each consuming gas independently.
ERC-1155: The Multi-Token Standard
ERC-1155 supports both fungible and non-fungible tokens within a single contract. Each token ID can have a supply of one (making it non-fungible) or a supply of many (making it semi-fungible or fungible). Key advantages include:
- Batch operations: Transfer multiple token types in a single transaction using safeBatchTransferFrom. This dramatically reduces gas costs for games, marketplaces, and airdrops involving multiple token types.
- Gas efficiency: A single contract handles all token types, reducing deployment costs and simplifying contract management. Batch minting is significantly cheaper than individual ERC-721 mints.
- Flexible token types: Mix unique items (supply of 1), limited editions (supply of 100), and fungible resources (supply of millions) in one contract. Perfect for gaming economies with diverse asset types.
Metadata and Storage
Both standards support metadata URIs pointing to JSON files that describe the token's properties, image, and attributes. For ERC-721, each token can have a unique URI via the tokenURI function. ERC-1155 uses a URI pattern with token ID substitution. Store metadata on decentralised storage like IPFS or Arweave for permanence and censorship resistance. The metadata JSON should follow the OpenSea metadata standard for broad marketplace compatibility, including name, description, image, and an attributes array for traits. On-chain metadata — storing attributes directly in the contract — is more expensive but eliminates dependency on external storage.
Choosing the Right Standard
Use ERC-721 when every token is truly unique and you need maximum marketplace compatibility — art collections, PFP projects, and real-world asset certificates. Use ERC-1155 when your project involves multiple token types, batch operations, or gaming economies where gas efficiency is critical. For projects that need both, ERC-1155 can handle everything in a single contract. At Born Digital, we evaluate each project's requirements and recommend the standard that best serves the use case, balancing gas costs, marketplace integration, and long-term flexibility.