On-Chain Art is an attempt to document on-chain projects.
Due to the high cost of storing data on the blockchain, most NFTs are stored in a database somewhere off-chain (which means off the "blockchain"). They store an identifier that points back to the description of the artwork and the corresponding visuals. If the server (or the database) to which the identifier points goes down, the art also disappears. Obviously, this sounds against the ethos of immutability of a distributed ledger.
This led to a new paradigm that became increasingly popular among smart contract developers and artists called on-chain art. On-chain because the advantage of having code, artwork and/or metadata on-chain creates permanence and immutability. They are permanently stored on the blockchain as long as the Ethereum network exists. Relying solely on the Ethereum Virtual Machine presents lots of constraints which stimulates creativity. 2
Data stored via calldata.
Data stored via SSTORE. External script necessary to render data.
Data stored via SSTORE. renderer built into contract. Outputs SVG or similar data URI.
The rating system on this site is taken from Dom Hoffman’s tweet