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📝 NFT Metadata: JSON Structure Explained

Learn how NFT attributes, images, and traits are stored

🖼️ What is NFT Metadata?

NFT metadata is the JSON data that describes your NFT. While the blockchain stores ownership, the metadata defines what your NFT actually is: its name, image, attributes, and more.

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On Blockchain

Token ID, owner address, contract rules

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In Metadata

Name, image, description, attributes, properties

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Visual Assets

Images, videos, 3D models, audio files

🔍 Interactive: Explore Metadata Structure

Click on any property to learn what it does. Hover to highlight the structure.

{
"name": "CryptoPunk #3100",
"description": "One of 9 alien punks, ultra-rare NFT",
"image": "ipfs://QmYwAP...3100",
"attributes": [3 items],
"external_url": "https://cryptopunks.app/cryptopunks/details/3100"
}
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Click on any property in the JSON to learn more about it

Why Metadata Matters

  • Discovery: How users find your NFT on marketplaces
  • Rarity: Attributes drive value and collectability
  • Interoperability: Standards ensure cross-platform display
  • Permanence: Storage choice affects long-term availability

⚠️ Common Mistakes

  • Storing metadata on centralized servers (can disappear)
  • Missing required fields (breaks marketplace display)
  • Non-standard attribute formats (limits filtering)
  • Huge uncompressed files (slow loading, high costs)

💡 Key Insight

The blockchain only stores a pointer (tokenURI) to your metadata. The actual JSON file lives off-chain, making storage choice critical. IPFS is popular because it is decentralized and content-addressed (file hash = permanent address), but trade-offs exist for every option.