ERC-721, ERC-721A, and ERC-721R: Which NFT Standard to Use?

By me.

I believe the best way to make money online is by following the trend. And NFT is the new trend that you need to take advantage of if you want to make money.

I know NFT is just in the beginning, and there isn’t a full guide that can help you make your NFT project. But the early adopters, like me, are doing their best to make the process as easy as possible.

As an NFT creator, you will need to determine what smart contract standard (Token standard) to use for your project. Therefore, I’m here to help you gain some information about these standards without diving into technical details.

What is a smart contract?

A smart contract is a sale agreement between the owner and buyer. It gets written with a programming language and sorted on the Ethereum blockchain in order to run automatically and endlessly.

For the NFT world, the main jobs of the smart contract are to verify ownership of an NFT to an address (Crypto address) and handle the transfer of the NFT from the owner’s address to another address.

What is a token standard?

A token standard is a set of rules and specifications, that a smart contract must have to be compatible with the common standards. There are many token standards of the Ethereum blockchain: ERC-20, ERC-223, ERC-721, and ERC-1155. ERC (Ethereum Request for Comments) is the abbreviation for Ethereum token standard.

ERC-721 and ERC-1155 are common standards for NFT projects. So, we are going to talk about ERC-721 and its variations.


Unlike ERC-20 used for fungible tokens like coins and money, ERC-721 handles tokens as a unique asset which makes it suitable for NFT.

Like I said before, ERC-721 is the most common standard in the NFT industry nowadays. Most successful NFT projects used ERC-721 as standard: Bored Ape Yacht, Crypto Punks, and Crypto Kitties.

This standard provides essential functionality to transfer and verify the ownership of NFTs. So, it may be the first and safe option for your project.

Projects that used ERC-721:


As the name suggests, it is a variation from the ERC-721 standard. It was created by the Azuki team and first used in their collection.

Compared to ERC-721, ERC-721A offers significant gas savings when minting multiple NFTs simultaneously. It will be possible to mint multiple NFTs for the same gas price as minting a single NFT with the ERC-721A contract.

This is a huge benefit for NFT collectors because, in recent months, Ethereum gas prices have always been high. 

from Azuki

from the image above, you can notice that the gas price doubles whenever you mint more NFT in ERC-721. But for ERC-721A the gas price approximately stays the same no matter how many times you mint NFTs.

But when do you need to implement ERC-721A? Well, it depends on your mint-per-user number or how many NFTs one user can mint in your collection. If you want to restrict every user to mint only one or two NFTs, you don’t need to use ERC-721A for your project.

Projects that used ERC-721A:


The ERC-721A provides improvements in gas-saving, while ERC-721R provides trustless refunds.

The ERC-721R allows buyers to ask for refunds within a certain period of time after they mint an NFT. This makes it more secure for the buyers to join a project without being afraid of rug-pull. Also, it pushes the creators of the project to deliver what they promised, otherwise, the people will just return the NFTs and get their money back.

This standard also helps the collection by keeping the floor price above the mint price, because if someone mint an NFT and then realized he doesn’t want it, he could easily ask for a refund instead of selling it in the open market for less than the mint price.

So, if you want to create an NFT project without showing your identity or having a lot of followers, This standard may be a good choice for your project. Because after all, no one is going to buy your NFTs if he doesn’t trust you.

Projects that used ERC-721R:

if you are looking for the most profitable and professional way to create your NFT collection, you can check our NFT-Generator. Or if you want to write and deploy your smart contract, you can contact us anytime you want.


Oh hi there đź‘‹
It’s nice to meet you.

Subscribe to our weekly NFT art tips - straight to your inbox

Leave a Comment

Your email address will not be published. Required fields are marked *

Shopping Cart