Bitcoin NFT marketplace Ordinals Market and Bitcoin Miladys jointly released the BRC-721E standard, allowing immutable and verifiable ERC-721 NFTs to be migrated to Ordinals without having to embed the entire NFT series in advance.

When bridging NFTs, BRC-721E encodes the data directly into a destruction transaction, which specifies a Bitcoin address to receive the inscription.

The standard is said to have low fee costs (it can be minted using just 100 bytes of JSON), support full metadata presentation via indexers, and the ability to upgrade and append on-chain data in the future.