ERC-721

ERC-721 is a standard for representing the ownership of different unique tokens, also known as “non-fungible tokens”. Tokens made to the ERC-721 standard are indivisible, distinguishable, and can represent a collection of assets. An ERC-721 token can also have different value than another token from the same smart contract.

Blockchain Ethereum
Type Non-fungible
Popular token Skullpunks-Og
Required Functions name, symbol, totalSupply, balanceOf, ownerOf, approve, takeOwnership, transfer, tokenOfOwnerByIndex, tokenMetadata
Released 2018
Use cases Collectables, Crypto games, Ownership
Explore ERC-721 APIs

Build with ERC-721 tokens on CryptoAPIs

Now that you know what ERC-721 is, integrate it: read ERC-721 token transfers, balances, and contract metadata across supported chains through one REST API.

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ERC-20
ERC-721
Omni Layer
TRC-20
TRC-721
BEP-20

Work with ERC-721 tokens via the CryptoAPIs API

Read ERC-721 token transfers, balances, and metadata across the chains CryptoAPIs supports — through one unified REST API, with no node to run.

Token transfers

List full ERC-721 token transfer history for any token contract or address, with pagination and real-time updates.

Token balances

Read current ERC-721 token holdings for any address in a single call.

Contract metadata

Get token contract details — symbol, name, decimals, and total supply — for any supported token.

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The standard of unique tokens

ERC-721 tokens are mostly used for collectables and as a way to tokenize unique items and assets in digital games. The standard provides basic functionality to transfer and track the ownership of NFTs.