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Encyclopedia Ethereum · Entry 122

NFT metadata: where the name, image and attributes live

AI-assisted research · separate automated verificationCorrections

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Ethereum
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2 cited records
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At a glance

Key facts

Key facts for NFT metadata: where the name, image and attributes live
FactDetailSource
Optional interfaceERC-721 defines an optional metadata extension with name, symbol and tokenURI.[1]
ReferencetokenURI can point to a JSON resource describing the token.[1]
SeparationThe token identifier and owner are distinct from the metadata resource.[1]
01

Follow the reference chain

A collection contract identifies a token and its owner. A metadata URI can lead to a JSON document, whose image field can lead to another resource. Each step can have different storage and availability properties.

A media preview in a wallet is the result of resolving those references. It is not necessarily the image bytes stored in the token contract.

02

Determine who can alter what is displayed

An implementation can construct or update metadata references under its own rules. A hosting operator may control a referenced server, while an upgrade authority may control future contract logic.

Check whether the URI and underlying content are fixed, content-addressed or administratively mutable. A unique token ID alone does not answer these questions.

03

Ownership of the token has a limited technical meaning

The ERC-721 interface defines token ownership and transfer behavior. It does not itself convey a universal license to reproduce the associated artwork or create a legal ownership registry.

Any content license or other rights need separate evidence from the relevant issuer or rights holder. Read those terms independently from the on-chain owner field.

Direct answers

Questions people ask

If an NFT is on-chain, must its image also be on-chain?

No. The token can have an on-chain ownership record while its metadata or media is referenced elsewhere. Inspect the actual URI and storage arrangement.

Inspect the evidence

The answer and key facts have stable claim links. These records retain the scope and qualification when reused.

NFT metadata describes a token, often through a URI returned by an optional metadata interface. The token’s ownership record and the referenced name, attributes or media are different things. Owning an NFT does not by itself guarantee that external content remains available, unchanged or accompanied by copyright ownership.

Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.

Link to this claim
Optional interface: ERC-721 defines an optional metadata extension with name, symbol and tokenURI.

Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.

Link to this claim
Reference: tokenURI can point to a JSON resource describing the token.

Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.

Link to this claim
Separation: The token identifier and owner are distinct from the metadata resource.

Scope: Ethereum · data through 2026-10-02. Verification: verified · 2026-10-02T18:12:41.505Z.

Link to this claim
Revision history
  1. — First publication after primary-source research and independent automated verification.

Source register

Sources and references

Retrieval dates and locators are recorded individually.
  1. Non-Fungible Token StandardEthereum Improvement Proposals

    Optional token metadata interfaces and the distinction between token and external resource.

    Locator: Specification: ERC721Metadata; Metadata Choices (metadata extension); NFT Identifiers · Version / scope: EIP/ERC-721; retrieved document hash recorded · Retrieved: 2026-10-02T17:03:42.309ZOpen source
  2. Proxy contractsOpenZeppelin

    Proxy implementation slots, delegated execution and upgrade authority.

    Locator: TransparentUpgradeableProxy; UUPSUpgradeable; ERC1967Proxy · Version / scope: OpenZeppelin Contracts 5.x · Retrieved: 2026-10-02T17:03:43.024ZOpen source
How this article was made

Research and drafting use AI assistance. A separate automated review checks claims against primary sources; no external expert or named human review is implied. Publication, substantive editing, source retrieval and verification are recorded separately. This version was independently checked by an automated reviewer on 2 October 2026.

Editorial method and corrections

Degrees of Satoshi editorial project. “NFT metadata: where the name, image and attributes live.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/nft-metadata/