A token standard is a clearly defined and widely agreed upon method for structuring and creating the technical underpinnings of an NFT. Using accepted token standards will ensure your NFTs are widely compatible and more easily trusted. Within the Ethereum ecosystem, there are two primary non-fungible token standards: ERC-721 and ERC-1155.
Originally proposed in 2017 via Ethereum Improvement Proposal number 721 (opens new window) (EIP-721 for short), the ERC-721 token standard was created in 2018 to allow for non-fungible assets to be generated on the Ethereum blockchain. The summary for EIP-721 described itself as “a standard interface for non-fungible tokens, also known as deeds.” The creation and success of early NFTs like CryptoPunks and CryptoKitties were part of the inspiration for developing the ERC-721 standard; it allowed the burgeoning ecosystem to begin building on a solid foundation. Today, the ERC-721 standard is the most widely used and supported type of NFT, and it undergirds a multi-billion dollar market.
# ERC-721AOriginally created by the Azuki team for its NFT launch in January 2022, ERC-721A (opens new window) is an emerging contract standard that is built off of the ERC-721 standard but includes some improvements. According to its creators, “ERC721A is an improved implementation of the IERC721 standard that supports minting multiple tokens for close to the cost of one.” Since successfully launching with this new implementation, several other high-profile NFT projects have gone on to utilize it as well.
Created half a year after the ERC-721 standard, the ERC-1155 standard was proposed in Ethereum Improvement Proposal number 1155 (opens new window) (EIP-1155 for short). According to the EIP’s summary, ERC-1155 is “a standard interface for contracts that manage multiple token types. A single deployed contract may include any combination of fungible tokens, non-fungible tokens or other configurations (e.g. semi-fungible tokens).” In comparison to ERC-721 tokens, ERC-1155 tokens are much more flexible and have a wider range of features.