What fields does ERC-721 metadata require?

The widely-supported schema uses name, description and image, plus an optional attributes array of trait objects. Marketplaces like OpenSea read these directly, so a valid file needs at least those three top-level fields with a reachable image URL.

Should the image link be IPFS or HTTPS?

For permanence, pin the image to IPFS and use an ipfs:// URI so the art cannot disappear if a server goes down. An HTTPS gateway URL also works and is sometimes easier for previews, but it depends on that host staying online.

How are attributes formatted?

Each attribute is an object with trait_type and value, for example { "trait_type": "Model", "value": "SDXL" }. Numeric traits like the seed can include a display_type of number. Marketplaces use these to build filters and rarity tables.

Why record the prompt and seed?

The prompt and seed make a generative piece reproducible and provable. Storing a prompt hash (rather than the full prompt) keeps the recipe private while still letting you prove provenance later by revealing the original prompt.

AI Art NFT Metadata Builder

AI art NFT metadata builder

Minting AI artwork as an NFT needs a metadata JSON file that marketplaces read to display the piece. The de-facto standard is the ERC-721 metadata schema — name, description, image, and an attributes array. This builder collects your fields and AI generation details and outputs a clean, compliant file ready to pin to IPFS.

How it works

You fill in the core fields and any generation attributes — model, seed, style and a prompt hash. The tool assembles them into a valid ERC-721 object, encoding each attribute as a { trait_type, value } pair so OpenSea and similar marketplaces can build filters and rarity tables. The seed is marked as a numeric display type. The output is pure, parseable JSON with no trailing commas or invalid fields.

Tips and notes

Pin to IPFS for permanence. Use an ipfs:// URI for the image so the art outlives any single server.
Store a prompt hash, reveal later. Keep the exact prompt private while still being able to prove provenance.
Use numeric display types for the seed and any edition number so marketplaces sort them correctly.
Validate before minting. Paste the output into a JSON validator — a single malformed character can make a marketplace fail to render your token.