> For the complete documentation index, see [llms.txt](https://nft-standards.gitbook.io/nft-standards-wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nft-standards.gitbook.io/nft-standards-wiki/custom-nft-platforms-add-ons/erc-721a-azuki.md).

# ERC 721A Azuki

Introduction:\
ERC-721A was developed by Azuki team

### Overview

Compared to the OpenZeppelin ERC-721 version, ERC-721A is more gas-cost-efficient, especially when minting more NFTs from one collection. For gas cost comparison, assuming 300 gwei and $3500/ETH, see the table below.

\| NUMBER MINTED | USD MINT COST (ENUMERABLE) | USD MINT COST (ERC721A) | DIFFERENCE |\
\| Mint 1 | $162.55 | $80.52 | $82.03 |\
\| Mint 2 | $283.86 | $82.76 | $201.10 |\
\| Mint 3 | $461.84 | $85.00 | $376.84 |\
\| Mint 4 | $526.46 | $87.23 | $439.23 |\
\| Mint 5 | $740.30 | $89.47 | $650.83 |

### How ERC-721A supports gas optimisation:

* Removing duplicate storage from OZ ERC721Enumerable
* Updating the owner’s balance once per batch mint request, instead of per minted NFT
* updating the owner data once per batch mint request, instead of per minted NFT

### Further reading:

* <https://www.erc721a.org/>
* <https://www.azuki.com/erc721a>
* <https://medium.com/@dumbnamenumbers/your-guide-to-erc721a-july-2022-f81f0be84a54>
* <https://github.com/chiru-labs/ERC721A/blob/main/docs/tips.md>