About
What this is
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.
On-Chain Stars
On-Chain Stars are based on Dom Hofmann’s tweet.
IPFS, Arweave, or content hash. [or pointer to regular server or no pointer at all]
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.
Stars reflect how the original contract stores the work; later improvements outside that contract are not counted. A raised + after the stars marks a level reached only through an opt-in mechanic or a retroactive contract added outside the original one, not what the original contract gives every token; the collection's On-Chain Storage section says how.
OnChainChecker
Every collection page also shows the score from onchainchecker.xyz, which inspects a contract and reports how much of the artwork it can find on chain. It is worked out automatically, where On-Chain Stars are a reading of how the contract stores its work. We record the score as given rather than recomputing it.
The two answer different questions, so they do not always agree, and a low score on its own does not mean the art is off chain. Some contracts keep their artwork on chain but expose it through their own custom methods rather than the standard ones, and a general-purpose check has no obvious way to follow them. Blitmap is the clearest example on this site: its images are stored on chain and rendered from the contract, and it scores zero.
The score links through to its full report, so you can check it yourself.
Open data
Everything this site records about its collections is published as one JSON file, dedicated to the public domain under CC0 1.0 — see the dataset page for what it holds, how it is made and where to download it.
Credits
0xchain.art was originally created and launched by Emre Colakoglu in collaboration with Jordan Punzalan. Our thanks to both of them for the vision and the groundwork that this archive is still built on.
Ownership has since been passed on to tokenfox, who keeps the site running today.
Disclaimer
The information on this site is collected on a best-effort basis from public sources and from submissions sent to us. This applies to everything a collection page shows: dates, ratings, scores and license information.
License information reflects what projects have stated on their websites, in their contracts or in their announcements at the time we checked. It is not authoritative, it may be outdated or wrong, and it is not legal advice. If you plan to use, remix or redistribute a project's artwork, do your own due diligence and verify the license with the project itself.