NFTs
Token URI
A reference (URL or IPFS address) pointing to metadata describing an NFT's properties.
What is Token URI?
A token URI is a string typically a URL or IPFS address that points to a JSON file containing an NFT's metadata: its name, description, image, and traits. It is the link between an on-chain token ID and its human-readable content.
How does Token URI work?
- When an NFT is minted, the contract stores a URI associated with its token ID.
- Marketplaces and wallets query the contract for the URI, then fetch the metadata JSON.
- IPFS URIs are immutable the same hash always returns the same content.
- Centralized server URIs can be updated but risk going offline permanently.
Why does Token URI matter?
Without a token URI, an NFT is just a number. The URI is what gives it a name, image, and traits everything users actually see and value.
Key features of Token URI
- Links on-chain token ID to off-chain metadata
- IPFS URIs are immutable and decentralized
- Follows ERC-721 metadata JSON standards
- Marketplaces depend on it to display NFTs correctly
Examples of Token URI
A Pudgy Penguin NFT uses an IPFS URI pointing to immutable metadata. Art Blocks uses a URI that dynamically generates SVG art on-chain.
A project that uses centralized server URIs risks losing all metadata if the server shuts down.