What is ERC721 on Solana?

If you’re coming from the EVM ecosystem, one thing you know well is ERC721. NFTs (non-fungible tokens) are at the heart of many blockchain applications, and ERC721 is one of the first standards developers learn when deploying NFT collections. On Solana, what is the ERC721 equivalent and how does it differ?

ERC721 sets a standard for Non-Fungible Tokens (NFTs), meaning each token is unique (in type and value) compared to another token. The ERC721 standard is utilized to represent individual tokens with distinct identifiers. Unlike ERC20 tokens, ERC721 tokens can possess unique characteristics and functions.

The Token Program (Plus Metadata)

On Solana, there isn’t a new smart contract for every NFT collection. Instead, NFTs are created under a single on-chain Token Program, the same one used for fungible tokens - just minted with a supply of 1. To store extra NFT details (like name, symbol, image URI, etc.), developers use the Metaplex Token Metadata Program.

Metaplex Metadata is an open-source protocol and platform for NFTs (Non-Fungible Tokens) and digital assets. Built on the Solana blockchain, Metaplex facilitates adding additonal metadata to tokens on Solana.

This is different from Ethereum, where you typically deploy a brand-new ERC721 contract for each collection. Why is there a single main program for NFTs on Solana? It’s due to Solana Account model, which separates state (the data) from execution logic (the program). Because Solana reuses the Token Program for all tokens, you don’t need to write and deploy a new NFT contract - just a new Mint Account with supply = 1.

NFTs Don’t Have Contract Addresses, Only Mint Addresses

On Ethereum, each NFT collection is identified by its Contract Address, and each token has a unique tokenId within that contract. On Solana, each NFT is identified by a Mint Address. The difference is that you don’t deploy a separate “NFT contract” - you just instruct the universal Token Program to create a new mint.

Because Solana’s Token Program is universal, there’s no concept of a unique “NFT contract address.” Instead, each NFT is a special SPL token (supply of 1) with its own Mint Address.

If you want a “collection,” you group multiple mint addresses together via a Collection Address in Metaplex, but each minted NFT is still just an SPL token with a unique Mint Address.

No Approval Flow Needed

On Ethereum, ERC721 often relies on approve or setApprovalForAll for external marketplaces or dApps to transfer your NFTs. On Solana, each NFT is stored in a user’s ATA(Associated token account), and a single transaction can include any necessary steps. There’s no separate approval flow - one atomic transaction can handle all instructions (e.g. transfer ownership, update metadata, etc.).

What Does A Solana Token Program Look Like?

A very rough translation of the Solana Token Program would look like this:

solidity
// SPDX-License-Identifier: MIT license
pragma solidity =0.8.28;

struct Mint {
    uint8 decimals;
    uint256 supply;
    address mintAuthority;
    address freezeAuthority;
    address mintAddress;
}

struct TokenAccount {
    address mintAddress;
    address owner;
    uint256 balance;
    bool isFrozen;
}

struct Metadata {
    string name;
    string symbol;
    string tokenURI;
}

contract Spl721 {
    mapping(address => Mint) public mints;
    mapping(address => TokenAccount) public tokenAccounts;
    mapping(address => Metadata) public nftMetadata;
    mapping(address => bool) public mintAddresses;
    mapping(address => bool) public tokenAddresses;

    function initializeMint(
        uint8 decimals,
        address mintAuthority,
        address freezeAuthority,
        address mintAddress
    )
        public
        returns (Mint memory)
    {
        require(!mintAddresses[mintAddress], "Mint already exists");
        mints[mintAddress] = Mint(decimals, 0, mintAuthority, freezeAuthority, mintAddress);
        mintAddresses[mintAddress] = true;
        return mints[mintAddress];
    }

    function setMetadata(
        address mintAddress,
        string memory name,
        string memory symbol,
        string memory tokenURI
    )
        public
    {
        require(mintAddresses[mintAddress], "Mint does not exist");
        nftMetadata[mintAddress] = Metadata(name, symbol, tokenURI);
    }

    function mintNFT(address toMintTokens, address mintAddress) public {
        require(mintAddresses[mintAddress], "NFT mint does not exist");
        require(mints[mintAddress].mintAuthority == msg.sender, "Only the mint authority can mint");
        require(mints[mintAddress].supply == 0, "NFT already minted");
        mints[mintAddress].supply = 1;
        address tokenAddress = address(uint160(uint256(keccak256(abi.encodePacked(toMintTokens, mintAddress)))));
        if (!tokenAddresses[tokenAddress]) {
            tokenAccounts[tokenAddress] = TokenAccount(mintAddress, toMintTokens, 0, false);
            tokenAddresses[tokenAddress] = true;
        }
        tokenAccounts[tokenAddress].balance = 1;
        tokenAccounts[tokenAddress].owner = toMintTokens;
    }

    function transfer(address to, address mintAddress, uint256 amount) public {
        address toTokenAddress = address(uint160(uint256(keccak256(abi.encodePacked(to, mintAddress)))));
        address fromTokenAddress = address(uint160(uint256(keccak256(abi.encodePacked(msg.sender, mintAddress)))));
        require(tokenAccounts[fromTokenAddress].balance >= amount, "Insufficient balance");
        require(amount == 1, "Only transferring 1 NFT at a time");
        require(tokenAccounts[fromTokenAddress].owner == msg.sender, "Not the NFT owner");
        require(!tokenAccounts[fromTokenAddress].isFrozen, "Sender token account is frozen");
        if (tokenAddresses[toTokenAddress]) {
            require(!tokenAccounts[toTokenAddress].isFrozen, "Receiver token account is frozen");
        }
        if (!tokenAddresses[toTokenAddress]) {
            tokenAccounts[toTokenAddress] = TokenAccount(mintAddress, to, 0, false);
            tokenAddresses[toTokenAddress] = true;
        }
        tokenAccounts[fromTokenAddress].balance -= amount;
        tokenAccounts[toTokenAddress].balance += amount;
        tokenAccounts[toTokenAddress].owner = to;
    }

    function freezeAccount(address owner, address mintAddress) public {
        require(mintAddresses[mintAddress], "Mint does not exist");
        require(mints[mintAddress].freezeAuthority == msg.sender, "Only the freeze authority can freeze");
        address tokenAddress = address(uint160(uint256(keccak256(abi.encodePacked(owner, mintAddress)))));
        require(tokenAddresses[tokenAddress], "Token account not found");
        tokenAccounts[tokenAddress].isFrozen = true;
    }

    function getMint(address token) public view returns (Mint memory) {
        return mints[token];
    }

    function getTokenAccount(address owner, address token) public view returns (TokenAccount memory) {
        return tokenAccounts[address(uint160(uint256(keccak256(abi.encodePacked(owner, token)))))];
    }

    function getMetadata(address mintAddress) public view returns (Metadata memory) {
        return nftMetadata[mintAddress];
    }
}


As you can see in the contract, instead of an approval flow, there is only a transfer function to move tokens. On Solana, a single transaction can call multiple smart contract functions atomically, removing the need for the approval flow. Another difference is that everything is stored in a token account on Solana, keeping the details of the owner’s tokens separate from the other state.

Where’s the NFT Metadata?

On Ethereum, ERC721 contracts often store a metadata URI or embed logic for fetching token metadata. On Solana, the Token Metadata Program (by Metaplex) handles NFT metadata in a separate account. You can include fields like name, symbol, description, image URI, and more—all without changing the underlying Token Program. This does mean there’s a separate instruction in your minting transaction to attach metadata. Since Solana can handle multiple program calls atomically in one transaction, you can easily create the mint and set up metadata in a single go.

Tradeoffs of Each Approach

Now that you have a general idea of how the token program and metadata program on Solana works, let’s go through some of the tradeoffs of each NFT standard.

ERC721

  • Highly customizable contracts
  • New contract deployment for each collection
  • Hard to index across many contracts
  • Metadata often defined in contract or via URIs
  • Requires individual audits

Solana NFT (SPL + Metaplex)

  • Single program for all NFTs
  • New NFTs created by transactions, not by new contracts
  • Easier to index since there’s one main program
  • Metadata stored in a separate progra
  • Reuses existing audited code

High-Level Comparison

Below is a table comparing the basic steps of deploying an ERC-721 token on Ethereum vs. creating an NFT (SPL token with metadata) on Solana. (On Solana, you can freely mint SPL tokens by using the spl-token command in the command-line tool.)

Step Ethereum (ERC-721) Solana (SPL + Metaplex)
1. Prepare Token Code Typically use OpenZeppelin’s ERC721 libraries. You create a Solidity file (e.g. MyNFT.sol). No custom contract needed for basic NFT functionality. The Token Program is already deployed. You just create a Mint Account (supply = 1).
2. Compile & Deploy Compile and deploy using Hardhat/Truffle (e.g. npx hardhat run deploy.js --network ...). Use a CLI (e.g. spl-token create-token --decimals 0) or an SDK tool (like Metaplex’s Candy Machine). No separate contract deployment is required.
3. Mint NFT Call the contract’s mint() function, which assigns the NFT to an address and usually sets token metadata URIs. Gas fees can vary. Run spl-token mint <MINT_ADDRESS> 1 or use Metaplex’s mint instructions to create exactly 1 supply. Transaction fees on Solana are typically very low.
4. Create Recipient Typically just a normal Ethereum address. Users must add the NFT contract address in many wallets to see it. Each user has an Associated Token Account (ATA). Wallets like Phantom automatically recognize ATAs for NFTs. No extra step to “add” the token, though it may appear under a “Collectibles” tab once recognized.
5. Check Results View on Etherscan or use an NFT marketplace like OpenSea. Often, users manually add the contract address to see tokens in some wallets. Use solana balance <ADDRESS> or spl-token accounts to see token holdings. You can also use a Solana Explorer or an NFT marketplace (Magic Eden, OpenSea Solana, etc.) to confirm the NFT’s presence.
6. Unique Identifiers Contract Address + tokenId. Mint Address. Each NFT is simply an SPL token with supply=1.
7. Collections All tokens in one contract typically represent a single collection. Collections are assigned via a “collection address” in Metaplex. You don’t deploy a dedicated contract.
8. Code Updates For major upgrades, you might use a proxy pattern or redeploy the contract. Only advanced devs typically do this. The Token Program is fixed. If you need advanced features (royalties, dynamic metadata, etc.), you can use or build separate on-chain programs. Metaplex also supports extensions like programmable NFTs.
9. Audit Requirements Each contract typically requires an audit, especially if you add custom minting logic, a marketplace, etc. The main Token Program and Metaplex Metadata Program have been audited multiple times. For a standard mint of an NFT, no additional contract audit is typically necessary.

Want to mint your own NFT on Solana? Check out this guide!

How to do ERC721 on Solana

Let's explore how to interact with the Token Program using solana/web3.js based on Ethereum's ERC721 interface structure.

As mentioned above, since NFT Collections on Solana are not tied to a specific contract, the concept of a tokenId does not exist. Therefore, to find the specific data of a token, you should use Mint Address or Collection Address.

How to do name()

solidity
function name() external view returns (string); // Returns the token collection name

You can use @metaplex-foundation/umi-bundle-defaults and @metaplex-foundation/mpl-token-metadata to fetch and parse an NFT’s off-chain metadata from its mint address.

jsx
import { createUmi } from "@metaplex-foundation/umi-bundle-defaults";
import { fetchDigitalAsset, mplTokenMetadata } from "@metaplex-foundation/mpl-token-metadata";
import { PublicKey } from "@metaplex-foundation/js";
const mintAddress = new PublicKey("Token Address");

async function name() {
  try {
    const umi = createUmi("https://api.devnet.solana.com");
    umi.use(mplTokenMetadata());
    const digitalAsset = await fetchDigitalAsset(umi, mintAddress);
    return digitalAsset.metadata.name;
  } catch (error) {
    console.error("Error fetching NFT name:", error);
    return null;
  }
}

name().then(nftName => {
    console.log("NFT Name:", nftName);
  })
  .catch(error => {
    console.error("Error:", error);
  });

How to do symbol()

solidity
function symbol() external view returns (string); // Returns the token collection symbol

You can also retrieve the symbol in the same way as name(), using @metaplex-foundation/umi-bundle-defaults and @metaplex-foundation/mpl-token-metadata.

jsx
import { createUmi } from "@metaplex-foundation/umi-bundle-defaults";
import { fetchDigitalAsset, mplTokenMetadata } from "@metaplex-foundation/mpl-token-metadata";
import { PublicKey } from "@metaplex-foundation/js";
const mintAddress = new PublicKey("Token Address");

async function symbol() {
  try {
    const umi = createUmi("https://api.devnet.solana.com");
    umi.use(mplTokenMetadata());
    const digitalAsset = await fetchDigitalAsset(umi, mintAddress);
    return digitalAsset.metadata.symbol;
  } catch (error) {
    console.error("Error fetching NFT symbol:", error);
    return null;
  }
}

symbol().then(nftSymbol => {
  console.log("NFT Symbol:", nftSymbol);
}).catch(error => {
  console.error("Error:", error);
});

How to do tokenURI()

bash
function tokenURI(uint256 _tokenId) external view returns (string); // Returns the tokenURI of the token

You can also retrieve the symbol in the same way as name(), using @metaplex-foundation/umi-bundle-defaults and @metaplex-foundation/mpl-token-metadata.

jsx
import { createUmi } from "@metaplex-foundation/umi-bundle-defaults";
import { fetchDigitalAsset, mplTokenMetadata } from "@metaplex-foundation/mpl-token-metadata";
import { PublicKey } from "@metaplex-foundation/js";
const mintAddress = new PublicKey("Token Address");

async function tokenURI( /* no tokenId */ ) {
  try {
    const umi = createUmi("https://api.devnet.solana.com");
    umi.use(mplTokenMetadata());
    const digitalAsset = await fetchDigitalAsset(umi, mintAddress);
    return digitalAsset.metadata.uri;
  } catch (error) {
    console.error("Error fetching token URI:", error);
    return null;
  }
}

tokenURI()
  .then(uri => {
    console.log("Token URI:", uri);
  })
  .catch(error => {
    console.error("Error:", error);
  });

How to do ownerOf()

bash
function ownerOf(uint256 _tokenId) public view returns (address) // Returns the owner of the tokenId token

We can check the owner of an NFT using the mint address instead of the tokenId.

jsx
import { Connection, PublicKey } from "@solana/web3.js";

const connection = new Connection("https://api.devnet.solana.com", "confirmed");
const mintAddress = new PublicKey("Token Address");

async function ownerOf( /*no tokenId*/ ){
  const largestAccounts = await connection.getTokenLargestAccounts(new PublicKey(mintAddress));
  const largestAccountInfo = await connection.getParsedAccountInfo(largestAccounts.value[0].address);
  return largestAccountInfo.value.data.parsed.info.owner;
}

ownerOf().then(owner => {
  console.log(owner);
}).catch(error => {
  console.error("Error:", error);
});

How to do transferFrom()

solidity
function transferFrom(address _from, address _to, uint256 _tokenId) external payable; // Transfers tokenId token from _from to _to

First, Let’s look at this code for understanding logic:

On Solana, each token is identified by its unique Mint address, and users store their balances in an Associated Token Account (ATA). In a transaction, the ATA address is used as the sender or receiver for transferring tokens. Unlike on Ethereum, where you directly call an ERC-20 contract, Solana handles token transfer logic through its native system program.

We can make a transaction’s transfer instruction through createTransferCheckedInstruction and send it through sendTransaction from @solana/spl-token.


jsx
import { Keypair, Transaction, Connection, PublicKey } from "@solana/web3.js";
import { createTransferCheckedInstruction } from "@solana/spl-token";

const connection = new Connection("https://api.devnet.solana.com", "confirmed");

// Replace with your real private key (as a Uint8Array)
const ownerSecretkey = [];
const ownerPrivatekeypair = Keypair.fromSecretKey(new Uint8Array(ownerSecretkey));

const fromPublicKey = ownerPrivatekeypair.publicKey; // The sender's public key
const toPublicKey = new PublicKey("Receiver's Wallet Address");

const mintAddress = new PublicKey("Token Address");

// Pre-existing ATA addresses (for `_from` and `_to`)
const ownerTokenAccount = new PublicKey("Associated Token Account of _from");
const receiverTokenAccount = new PublicKey("Associated Token Account of _to");

// For an NFT, decimals = 0 and amount = 1
async function transferFrom(_from, _to) {
  try {
    const tx = new Transaction().add(
      createTransferCheckedInstruction(
        ownerTokenAccount,              // _from's ATA
        mintAddress,
        receiverTokenAccount,           // _to's ATA
        ownerPrivatekeypair.publicKey,  // Authority for `_from` (the private key must match this public key)
        1,                              // amount = 1 NFT
        0                               // decimals = 0 for NFT
      )
    );
    
    // Send transaction (simple version)
    await connection.sendTransaction(tx, [ownerPrivatekeypair]);
    return true;
  } catch (error) {
    console.error("Error in transferFrom:", error);
    return false;
  }
}

transferFrom(fromPublicKey, toPublicKey)
  .then(result => {
    console.log("transferFrom result:", result);
  })
  .catch(error => {
    console.error("Error:", error);
  });

How we can check receiverTokenAddress through receiverAddress? We can use getOrCreateAssociatedTokenAccount. It will retrieve the associated token account, or create it if it doesn't exist.

jsx
import { Keypair, Transaction, Connection, PublicKey } from "@solana/web3.js";
import { createTransferCheckedInstruction, getOrCreateAssociatedTokenAccount } from "@solana/spl-token";

const connection = new Connection("https://api.devnet.solana.com", "confirmed");

// Insert your private key as a Uint8Array
const ownerSecretkey = [];
const ownerPrivatekeypair = Keypair.fromSecretKey(new Uint8Array(ownerSecretkey));

const fromAddress = ownerPrivatekeypair.publicKey;  // The sender's public key
const toAddress = new PublicKey("Receiver's Wallet Address");

const mintAddress = new PublicKey("Token Address");

// For an NFT: decimals = 0, amount = 1
async function transferFrom(_from, _to) {
  try {
    // Retrieve (or create if missing) the sender's ATA
    const ownerTokenAccount = await getOrCreateAssociatedTokenAccount(
      connection,
      ownerPrivatekeypair,    // Fee payer
      mintAddress,
      _from
    );

    // Retrieve (or create if missing) the receiver's ATA
    const receiverTokenAccount = await getOrCreateAssociatedTokenAccount(
      connection,
      ownerPrivatekeypair,    // Fee payer (use the receiver if needed)
      mintAddress,
      _to
    );

    // Create transaction with a transfer of 1 NFT (decimals=0)
    const tx = new Transaction().add(
      createTransferCheckedInstruction(
        ownerTokenAccount.address,
        mintAddress,
        receiverTokenAccount.address,
        ownerPrivatekeypair.publicKey,
        1, // Always transfer exactly 1 (NFT)
        0  // decimals = 0 for an NFT
      )
    );

    // Send the transaction
    await connection.sendTransaction(tx, [ownerPrivatekeypair]);
    return true;
  } catch (error) {
    console.error("Error in transferFrom:", error);
    return false;
  }
}

transferFrom(fromAddress, toAddress)
  .then(result => {
    console.log("Transaction result:", result);
  })
  .catch(error => {
    console.error("Error:", error);
  });

Want to explore more features? Check out this guide!

Node storing all data and participating in consensus

  • Ethereum: Archive Node
  • Solana: [n/a]

Node storing some data and participating in consensus

  • Ethereum: Full Node
  • Solana: Consensus Node

Node storing some data and not participating in consensus

  • Ethereum: Light Node
  • Solana: RPC Node
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