What is an NFT Standard on Solana?

NFT standards dictate how a unique asset is represented on-chain, and to date, Solana has implemented three distinct standards. Metaplex NFTs were Solana's first iteration, followed by programmable NFTs (pNFTs) in 2023, designed to force royalties, and finally Metaplex Core in 2024, which has become the standard for most Solana assets. Each of these NFT standards carries significant differences with regards to minting cost and what programs are permitted to interact with each. Understanding these differences can help artists determine their optimal mint strategy, or buyers understand exactly what they're purchasing.

Legacy NFTs

A legacy NFT is an attempt to work-around the Solana's SPL-token implementation to create unique assets. A legacy NFT requires an SPL mint with a supply of 1 and 0 decimals (effectively making it unique), a metadata account (which stores the title and image of the NFT), and a master-edition account to prove the mint is a singular asset. This results in 3-4 separate accounts per NFT. To put it in real-world terms, it's like a property deed that is stored in a 3-ring binder. The property deed is in one section, a photo of the house is in another section, and the terms of the contract with the lender are kept in a third.

Core replaces this binder with a single laminated ID.

How pNFTs Changed The Rules

pNFTs were developed in response to a crisis that wasn't an engineering problem, it was an economic one. During the royalty wars of 2022-23, secondary marketplaces started allowing users to bypass royalties for creators. This caused revenues for many of Solana's artists and collections to plummet. Tensor, Metaplex, and many marketplaces launched features that made royalties optional.

In response, pNFTs were developed which restrict which programs were allowed to transfer the asset. The result is that all secondary sales of pNFT assets will enforce creator royalties. It is technically impossible for marketplaces to allow users to bypass these royalties, because the asset itself refuses transfers from programs which do not collect royalties.

How Metaplex Core Improved on the NFT Standard

Metaplex released Metaplex Core in 2024 to improve and replace the pNFT implementation, as it allows Core creators to implement similar logic, along with additional features. The core idea behind the Core implementation is that it reduces the number of accounts per NFT from 3-4 down to just 1. This has significant economic implications: Core assets cost roughly 0.003 SOL to mint (about $0.24 at an $80 SOL price), whereas legacy assets cost 0.022 SOL to mint (roughly $1.76 at the same price). Over a large collection with 10,000 assets, this would represent a drop from roughly 220 SOL per collection to just 30 SOL per collection. For most independent artists, or small teams, this is not an abstraction but actual, material money.

Core also has the added benefits of being a more flexible implementation that allows plugins to add functionality like enforcing royalties, "freezing" assets to prevent transfers, or adding additional data and metadata on the asset itself.

For those that have even more ambitious plans and wish to mint in the millions of NFTs, it may also be helpful to be familiar with a compressed NFT standard (cNFTs).

How This Compares to the Ethereum NFT Standard

The Ethereum standard is quite similar. In Ethereum, there is an ERC-721 standard for non-fungible assets (similar to Metaplex Core) and an ERC-1155 standard for semi-fungible assets, and a separate "royalty" implementation known as EIP-2981. However, the royalties aspect is also optional for Ethereum marketplaces (the majority of Ethereum marketplaces made the collection royalties "opt-in" in late 2022). This resulted in similar issues where royalties would not be paid, causing controversy and a drop in revenue. Neither ecosystem managed to resolve the issue by a "social agreement" where marketplaces would simply honor royalties because it was the right thing to do, and both chains ultimately turned to technical implementations.

Solana was able to enforce this by making a "pNFT rule" that requires assets to be passed through programs which enforce royalties (and subsequently through plugins for Core). However, there is a significant caveat here: a marketplace protocol that has not integrated pNFT rules (or a Core plugin enforcing royalties) would be unable to custody the asset. This has implications for liquidity, as the asset cannot be moved outside the program implementing the restriction.

The second major problem this raises is the question of compatibility and fragmentation. Since the Solana blockchain has multiple implementations of the NFT standard living side by side, it is important for marketplaces to be aware of both pNFTs and Core in order to provide a cohesive user experience. Some NFT wallets and indexing sites currently only support certain standards, so you can't interact with some Solana NFTs until you figure out the proper account type for the asset in question.

Why do NFT Standards Even Matter?

NFT standards are the building blocks for everything related to an NFT, including the costs associated with the asset, royalties, and even future potential upgrades.

In the context of a creator, this means that the standard they pick has significant material cost implications, both on the frontend and the backend. For example, if I were launching an NFT project today on the Solana chain, picking Core as my preferred standard would mean I could mint the entire project, in this hypothetical example with 10,000 NFTs for less than 30 SOL (assuming the same $80 SOL price I quoted earlier) as compared to the 200+ SOL I would have to spend to achieve the same project using legacy NFTs. In addition, it would also ensure that creators in my project will collect royalties. Metaplex Core assets have the same royalty-enforced mechanics as pNFT assets as long as the plugin is installed, so I don't need to rely on a social contract or the goodwill of marketplaces. Both the Tensor marketplace and Magic Eden fully support trading these assets.

For a buyer of a Solana NFT, this means that they should be aware of which standard an NFT belongs to, since that defines the mechanics and costs of that asset. For example, if you were buying a legacy NFT, it doesn't matter what standard you are using because they can't enforce creator royalties; the marketplace will just choose to honor them. However, if you're purchasing a pNFT or Core NFT with the plugin installed, you will have to pay the creator fee on all secondary purchases. This fee will also be displayed to you before making a purchase on the marketplace. In a similar vein, it's generally a good idea to check the metadata and properties for Solana assets on an explorer such as Solscan, in order to be informed about which standard the asset is using. There are many cases where an asset won't actually be compatible with a certain program or wallet, or even if it is compatible with a platform you want to use, if that program doesn't yet support a specific standard (e.g. Metaplex's legacy NFT standard) you may not be able to move assets to a specific wallet that you want to.

Do all sales of pNFTs have to pay royalties?

Yes! The only way a pNFT can be bought or sold is through a program that pays royalties. However, you can transfer pNFTs to wallets (or to other people), and these transfers do not include royalties or any other fees. Unfortunately, there is no mechanism on any chain to enforce royalties in private sales between wallets, and pNFTs do not change this.