NFT Rarity Checker

WHAT IT DOES

NFT Rarity Checker analyzes the metadata of NFT collections to determine how rare each token is based on its traits. By fetching the tokenURI for each NFT and parsing the attributes from the metadata JSON, the tool calculates trait frequencies across the collection and assigns a rarity score to each token. The rarity score is the sum of the inverse frequency of each trait — the rarer a trait, the higher its contribution to the score. Tokens with higher scores are considered rarer. The tool displays the collection name, symbol, total supply, and a ranked list of tokens with their rarity scores and detailed trait breakdowns.

HOW TO USE

Connect your wallet using the BGWallet bridge (MetaMask or any Web3 wallet). Ensure you are on the same network as the NFT collection — Ethereum, BNB Chain, Polygon, Arbitrum, Optimism, Base, or any EVM chain. Enter the NFT contract address in the input field. Optionally, enter a specific token ID to check only that token's rarity. Click "Check rarity" to start the analysis. The tool will fetch the tokenURI for each token (or just the specified one), retrieve the metadata JSON from IPFS or HTTP, parse the attributes, calculate trait frequencies, and rank the tokens by rarity. Results are displayed in a table with rank, token ID, rarity score, and a breakdown of traits with their frequencies.

TECHNICAL MECHANISM

The tool first reads the NFT contract's name, symbol, and totalSupply using the ERC-721 standard interface. For each token ID (or the specified one), it calls tokenURI(tokenId) to get the metadata URI. The URI may be an IPFS link (ipfs://) or an HTTPS URL. If IPFS, the tool converts it to an HTTP gateway URL (https://ipfs.io/ipfs/). It then fetches the metadata JSON, which typically contains an "attributes" array with trait_type and value pairs. The tool aggregates all trait-value combinations across the collection, counting how many tokens have each trait value. For each token, it calculates a rarity score as the sum of (1 / frequency) for each of its traits. Tokens are then sorted by score descending (rarest first). The tool limits checking to the first 50 tokens for performance and to avoid excessive RPC calls, but displays the total supply for context.

WHAT IT CANNOT SEE

The tool cannot calculate rarity for collections that do not expose off-chain metadata via tokenURI, or where the metadata is not accessible (broken IPFS gateways, expired URLs, or authentication-required endpoints). It cannot verify rarity against external scoring systems like Rarity.tools, OpenSea's rarity ranking, or market prices — it uses its own frequency-based calculation only. It cannot detect duplicate or fraudulent attributes, such as traits that are identical but have different names. It cannot rank NFTs that use randomized or dynamic metadata that changes per view. It cannot handle ERC-1155 collections. It cannot display images or interactive previews of the NFTs. It cannot detect if the metadata is modified after minting. The tool is read-only and does not sign any transactions.

PLEASE NOTE

This tool works exclusively on EVM-compatible chains (Ethereum, BNB Chain, Polygon, Arbitrum, Optimism, Base, Avalanche C-Chain, Fantom, and others). Solana, Tron, Starknet, SUI, TON, Aptos, Bitcoin, Cosmos, and XRP are not supported. The tool only supports ERC-721 NFT collections — ERC-1155 is not supported. Metadata is fetched live from IPFS or HTTP endpoints, so performance depends on gateway response times and the metadata size. The tool does not store any data — all reads happen live. The rarity calculation is based solely on trait frequencies within the checked subset; for full collection rarity, the tool would need to scan all tokens, which may be limited by RPC constraints. The tool is provided as-is with no warranty or liability. Always verify contract addresses from trusted sources.