What is NFT rarity?
- Author
- CRYPTO PORT Editorial
- Published
- Updated
- Reading time
- 4 min
In short
Rarity scores rank items in a collection by how uncommon their traits are. There is no standard formula, so rankings differ between sites. Being rare and being wanted are separate things, and a score says nothing about the second.
Key points
- Scores items from how uncommon each trait is
- No standard formula — rankings vary by site
- Traits come from the values listed in the metadata
- Rarity and demand are two different questions
Definition
A measure of how uncommon an individual NFT's traits are within its collection, computed from the frequency of each value in the collection's metadata.
Generative collections assemble each item from candidate values for traits like background, clothing and headwear. Rarity is computed from how often each value appears. Some formulas sum the inverse of each trait's frequency, some multiply them, some use an information-theoretic measure — and the ranking shifts depending on which is used.
Trait values live in the metadata JSON, so if the metadata is replaced, the rarity calculation changes with it. Teams sometimes also add new trait values later, which shifts the relative rarity of every existing item.
The key point is that having a rare trait and having someone who wants it are separate. A trait appearing in 0.1% of items means nothing if no buyer cares about it. A rarity rank is a statistic about the collection, not a measurement of demand.
Watch out for
- · A high rarity rank does not mean the item can be sold
- · Rankings differ by calculator, so do not lean on a single number
- · Added traits or changed metadata can alter rarity after the fact