What is IPFS and how is it used in blockchain?

IPFS is a peer-to-peer protocol for sharing files that identifies data by what it contains rather than where it is stored. Its documentation describes it as a set of open protocols for addressing, routing and transferring data on the web. In crypto, IPFS is widely known as the place where many NFTs keep their images and metadata.

What is IPFS in blockchain?

IPFS is not a blockchain. Its docs describe it as an open, participatory network of nodes plus the protocols they use to share content-addressed data. Blockchains use it because storing large files directly on-chain is expensive, so a smart contract often stores only a short IPFS link while the file itself lives on IPFS.

The key idea is content addressing. On the normal web, a link points to a location, such as a server address. On IPFS, a link is a content identifier, or CID, built from a cryptographic hash of the data. Change one byte of the file and the CID changes. Add the same file on two different nodes with the same settings and you get the same CID. Older CIDs start with "Qm", while newer ones usually start with "bafy".

What is IPFS storage and how does pinning work?

IPFS itself is a protocol, not a storage provider. Nodes keep copies of data only temporarily unless someone pins it. Pinning tells a node to keep the content and not delete it during cleanup. Projects can run their own nodes or pay a remote pinning service.

This matters for NFTs. The IPFS docs recommend that NFT metadata and smart contracts point to content with an ipfs:// link followed by the CID, since anyone can then check that the file matches. If nobody pins the data, though, it can become unavailable even though the token still exists. For how token metadata connects to the NFT itself, see how NFTs work.

What is ipfs.io?

ipfs.io is a domain associated with the IPFS project and is also used as an HTTP gateway. A gateway lets an ordinary browser load IPFS content through a regular web address. The IPFS docs advise against hardcoding gateway links such as ipfs.io into NFTs, because a gateway link breaks if that operator goes offline, while an ipfs:// link does not depend on any one server.

Separately, if you see "IPFS" on a bank statement, it may refer to Imperial PFS, a commercial company that finances insurance premiums and has no connection to the protocol.

How are IPFS and Filecoin related?

IPFS and Filecoin are related projects supported by Protocol Labs. According to Filecoin's docs, IPFS lacks built-in incentives or guarantees that anyone will keep storing a file. Filecoin provides that incentive layer, giving storage providers a reason to keep data available. Put simply, IPFS handles how content is addressed and shared, and Filecoin adds an economic reason to keep it stored.