Bitcoin Ordinals are a protocol launched in January 2023 by developer Casey Rodarmor that enables individual satoshis (the smallest unit of Bitcoin, 1 BTC = 100,000,000 satoshis) to be tracked, inscribed with arbitrary data, and transferred — effectively creating NFTs and tokens natively on the Bitcoin blockchain without any Layer 2 or sidechain. The key insight is that satoshis can be given a unique number (“ordinal number”) based on their mining order, and data can be “inscribed” directly into Bitcoin transactions using the “witness” field (enabled by the Taproot upgrade in 2021).
Why Ordinals matter: Bitcoin was long considered a settlement layer with limited programmability — Ordinals changed this by enabling on-chain digital art, collectibles, and even fungible tokens (BRC-20) directly on Bitcoin. This sparked fierce debate in the Bitcoin community: traditionalists argued inscriptions bloat the blockchain and raise fees; proponents saw a new revenue stream for miners and a wave of Bitcoin-native culture. The Ordinals boom in 2023 drove Bitcoin transaction fees to multi-year highs as inscription demand competed with regular transactions. Notable Ordinals collections include Bitcoin Frogs, NodeMonkes, and Quantum Cats. The ecosystem spawned related innovations: BRC-20 tokens (fungible tokens inscribed on Bitcoin) and Runes (a more efficient fungible token standard). Ordinals demonstrated that Bitcoin’s base layer is more programmable than many assumed.
Example: An artist inscribes a 10KB pixelated image of a frog onto Bitcoin satoshi #1,234,567. This inscription is permanently stored on the Bitcoin blockchain and can be bought, sold, and verified by anyone — a native Bitcoin NFT requiring no Ethereum or separate smart contract.
Learn more: Ordinals — Documentation
