A token standard for non-fungible Ethereum tokens.

What Is ERC-721?

ERC-721 refers to a token standard that can be found on the Ethereum blockchain.

The more common term used to refer to these assets is non-fungible tokens — an asset class that exploded in popularity in late 2020 and early 2021.

Non-fungible tokens (or NFTs for short) refer to tokens that have unique characteristics, setting them apart from other tokens.

A $10 note is an example of something that is fungible. If you lend one of these banknotes to a friend, you don’t need to receive the exact same one back as they are all identical.

A plane ticket or a trading card is an example of something non-fungible. Although two plane tickets may look the same, one may offer an economy trip to New York, while another will guarantee you a first-class trip to Barbados. As a result, they cannot be swapped on a like-for-like basis.

ERC-721 tokens help bring this concept to the blockchain, ensuring that distinctive details about an asset can be immortalized. NFTs can be used to provide digital representation of a one-of-a-kind artwork, with ownership that is easily proved through blockchain records. This can help clamp down on counterfeiting.

There is a firm belief in the Ethereum community that ERC-721 could have a number of exciting applications — far beyond the collectible CryptoKitties that made this asset class famous. A number of rival blockchains (Binance Smart Chain being one of them) have also released token standards that offer similar characteristics to ERC-721.