Where's Your NFT? How to Store NFT Metadata

With so much noise around NFTs, we’re pulling the curtain and going behind the scenes to talk about what truly matters: metadata.


In recent blog posts, we’ve talked about the future of NFTs and the future of NFT marketplaces, trying to please the growing demand for knowledge around non-fungible tokens. Today, we’re going to dig even deeper into the notorious online asset, giving you all the information you need to know about how to store NFT metadata.

What is an NFT?

For most people, NFTs are just JPGs or PNGs of pixelated images and don’t make much sense. That couldn’t be further from the truth. To quote our “Crypto 101: NFTs and the Metaverse Explained” article, “an NFT stands for a non-fungible token. It's a digital asset built on blockchain technology that shows you own a digital item, whether an image, video, or gaming item. NFTs are interesting because you can verify your ownership of different items on the blockchain. You can buy and sell NFTs in exchange for crypto.”

To add more information to that description, non-fungible means unique, one-of-a-kind. How do these cryptographic assets differ? They all carry unique identification codes and metadata. Talking of metadata, let’s segway to the next section of our article.

What is an ERC721 token?

ERC721 is ​​the token standard on Ethereum that NFTs are built on, making them unique and, consequently, not interchangeable.

What is NFT metadata?

Put simply, NFT metadata is the details/properties that define a digital asset. All the details that make your NFT look and sound the way it does. Some of the most commonly used metadata are:

  • file name
  • file description
  • transactional history
  • any information the creator feels important to mention

What most people don’t know about NFT metadata is that they exist as a different entity, and they are not the same thing as the NFT. The metadata is stored in a different location, which is critical for preserving the NFT’s value.

Before diving into the storing process, let’s dissect this idea further. What happens with NFT metadata is that the digital asset itself includes a link that points to the metadata, which exists elsewhere online. Where elsewhere? This is where things get interesting. Storing metadata can happen on the chain and off the chain.

On-chain metadata

This type of metadata is integrated with the on-chain NFT itself, so the NFT “information” also lives on the blockchain. Storing on the chain comes with a set of challenges that can potentially endanger the value of the NFT. As you know, links die, hosting platforms don’t exist forever, and if anything were to happen to the blockchain, the NFT intrinsic value and ownership could be affected.

Off-chain metadata

How do you ensure the safety of your NFT metadata with perpetual accessibility? Some people use Cloud storage systems or servers. While those options are reasonably safe, considering the value of NFT investments, they are not bullet-proof solutions. They are both hackable and subject to malfunctions. This is where the InterPlanetary File System IPFS comes in.

What is an InterPlanetary File System (IPFS) service?

IPFS is a peer-to-peer network storing and sharing metadata in a distributed file system. IPFS interacts with Filecoin, a peer-to-peer network that stores files with built-in economic incentives to ensure files are stored reliably over time. This is not data storage the way you’re used to. In this new paradigm, companies do not own user data. Instead, individuals maintain ownership of their data.

The system enables users to store and retrieve content based on a “fingerprint” of the content (a cryptographic hash called a CID) distributed among several independent storage providers. This begs the following question: how do you know which file storage providers are most trustworthy?

This is where Filecoin provides the framework for a reputation system and a way to interact with the different storage providers. Think of CID as a string of code that references the relevant content. Here’s an example of what a CID hash looks like:


For more information on CIDs, refer to the Content Addressing guide provided by IPFS.

If the storage provider goes out of business or for some reason is inaccessible, you still have access to your metadata.

Free NFT storage

To make things even more incredible, IPFS launched NFT.Storage, a free service where users can save up to 31GiB in size per individual upload.

IPFS benefits

  • CID files are immutable and cannot be altered by third-party entities
  • By retrieving data from multiple sources and not a centralized server, content retrieval is faster and more efficient
  • Creators can distribute their work without cost
  • Data load faster as it has higher bandwidth
  • There is only one copy of each resource, making duplication impossible and authentication much simpler
  • There is no single point of failure as IPFS content is housed in several locations in a shared, peer-to-peer network using a distributed hash table (DHT)

Final thoughts

NFT metadata should never be an afterthought but one of the main components of any NFT project or investment. By linking to the metadata outside the smart contract, you’re strengthening the NFT architecture, decreasing computational expenses, and ensuring the asset’s authenticity is stored on the blockchain while the asset itself is stored off-chain.

About Polkastarter
Polkastarter is the leading decentralized fundraising platform enabling crypto’s most innovative projects to kick start their journey and grow their communities. Polkastarter allows its users to make research-based decisions to participate in high-potential IDOs, NFT sales, and Gaming projects.

Polkastarter aims to be a multi-chain platform and currently, users can participate in IDOs and NFT sales on Ethereum, BNB Chain, Polygon, Celo, and Avalanche, with many more to come.

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