Web3 Academy — Learn Blockchain, Solidity & DeFi

ERC-721 defines the standard for non-fungible tokens (NFTs). Each token has a unique tokenId. Key functions: ownerOf(tokenId), safeTransferFrom(), approve(), setApprovalForAll(). The tokenURI(tokenId) function returns metadata (usually a JSON file with name, description, and image URL). ERC-721A is an optimized implementation that reduces gas costs for batch minting. ERC-1155 is a multi-token standard that supports both fungible and non-fungible tokens in a single contract.

💡 Key Takeaway

This lesson covers the fundamental concepts. Make sure you understand these before moving to the next chapter.

ERC-721 NFT Standard