How GradeMyNFT Works
The grading system, explained.
The Core Idea
NFTs are unique in that every single transfer is permanently recorded on-chain. Unlike physical collectibles where grading requires a human expert to inspect the item, NFT grading can be done automatically and objectively. The more an NFT has changed hands through sales, the more "circulated" it is, just like a dollar bill that's passed through hundreds of wallets.
Smart Transfer Classification
Not all transfers are equal. We classify every transfer into one of four types:
The original creation event. Neutral. Everyone starts here.
A sale via OpenSea, Blur, LooksRare, etc. This is what lowers your grade: real circulation events.
A transfer with no ETH value exchanged, typically right after a purchase. We detect these as hardware wallet security moves and apply minimal penalty.
Other transfers: gifts, wallet migrations, etc. Minor deduction.
Hardware Wallet Detection
A very common pattern is: buy on a marketplace with a hot wallet → immediately transfer to a hardware wallet for safe keeping. Without smart classification, this would look like 2 transfers and hurt your grade unfairly.
We detect this by checking: was there ETH value in the transaction? Was a marketplace contract involved? Did the receiving wallet hold it for a long time? If it looks like cold storage, it's treated as such.
The Scoring Formula
Start: 100 points
1st sale: −15
2nd sale: −12
3rd sale: −10
4th–6th sale: −8 each
7th–11th sale: −5 each
12th+ sale: −3 each
Cold storage moves: −1 each (max −5)
Age bonus (per 6 months): +1 (max +5)
Genesis holder (never left mint wallet): +5
The tapered penalty for repeat sales means a heavily flipped NFT eventually bottoms out rather than going negative. Floor is 1.
Grade Scale
Data Sources
Transfer history is sourced from the Ethereum blockchain via Etherscan. NFT metadata (images, names) is fetched from OpenSea when available. All data is on-chain and publicly verifiable. Nothing is invented or estimated.
Currently supports ERC-721 tokens on Ethereum mainnet. Polygon, Base, and Solana support coming soon.