ERC721A vs ERC721

ERC 721A is an improvement standard for ERC721 tokens. It was proposed by the Azuki team and used for developing their NFT collection.

Compared with ERC721, ERC721A is a more gas-efficient standard to mint thousands of NFTs simultaneously. It allows developers to mint multiple NFTs at the same gas price. This has been a great improvement due to Ethereum’s sky-rocketing gas fee.

The goal of ERC721A is to provide a fully compliant implementation of IERC721 with significant gas savings for minting multiple NFTs in a single transaction.

This table shows how the gas used for ERC721A for an increasing number of mints scales at a much smaller constant factor. This may be the a good answer for high ethereum gas fees for multiple mints.

Cheaper batch mints sound awesome! Are there any downsides to all this good? (Yes)

The tradeoff of the ERC721A contract design is that functions using transferFrom and safeTransferFrom cost more gas, which means it may cost more to gift or sell an ERC721A NFT after minting than a normal ERC721 NFT.

The ERC721A _safeMint logic makes efficiency gains by not setting explicit owners of specific tokenIDs when they are consecutive IDs minted by the same owner.