Crypto Gloss

Ordinals

Bitcoin Ordinals is a protocol created by Casey Rodarmor and launched in January 2023 that assigns sequential serial numbers (ordinal numbers) to individual satoshis (the smallest unit of bitcoin) and enables arbitrary data — images, text, HTML, code — to be inscribed directly into Bitcoin transactions and stored permanently on the Bitcoin blockchain, creating what are effectively Bitcoin-native NFTs called “inscriptions” without requiring smart contracts or a separate layer.

The Technical Foundation

Ordinal theory:

  • Bitcoin has 2.1 quadrillion satoshis (100 million sats per BTC)
  • Ordinal theory assigns each sat a unique, sequential number based on the order it was mined
  • Sat 0 was in the genesis block; satoshis are numbered in mining order
  • This numbering is theoretical (Bitcoin doesn’t natively track individual sats) but deterministically computable

The inscription:

  • When a satoshi is identified by its ordinal number, data can be “inscribed” onto the transaction that transfers it
  • Taproot (a 2021 Bitcoin upgrade) made this possible by allowing large data payloads in witness data
  • The inscribed data lives in the Bitcoin transaction permanently — it’s part of the blockchain

No smart contract required:

  • Unlike Ethereum NFTs, Ordinals don’t use smart contracts
  • The NFT-like property is achieved purely through transaction data and the ordinal numbering system
  • This is both a feature (simplicity, Bitcoin’s security) and a limitation (no programmability)

Inscriptions

An inscription is:

  • A specific satoshi with ordinal number X
  • Data (an image, text, HTML, code) permanently stored in the transaction that holds that sat
  • Viewable at ordinals.com or other inscription explorers

Common inscription types:

  • JPEG/PNG images (PFP-style NFTs on Bitcoin)
  • SVG (on-chain generative art)
  • HTML (interactive web content)
  • Text (JSON, BRC-20 token deployments)
  • Video and audio

Notable Inscription Collections

Bitcoin Punks: Among the first inscription PFP collections; homage to CryptoPunks.

Ordinal Punks: Early high-value collection; 100 pieces; first large ordinal PFP project.

Taproot Wizards: Udi Wertheimer’s collection; includes the largest Bitcoin transaction in history.

Bitcoin Frogs: High-volume PFP collection; became one of the first high floor-price ordinal collections.

Sub10k: Any inscription with a number below 10,000; rarity from early inscription status.

BRC-20 Tokens

A secondary use case for Ordinals:

  • Casey Rodarmor did not create BRC-20 — it was invented by pseudonymous developer Domo
  • BRC-20 uses text inscriptions to define and transfer fungible tokens on Bitcoin
  • Technically fragile compared to Ethereum’s ERC-20; requires off-chain indexers to track balances
  • Generated enormous fee pressure on Bitcoin in 2023

Controversy

Bitcoin community split:

  • Core Bitcoin developers and “Bitcoin maximalists” largely opposed Ordinals as blockchain bloat
  • Argument against: Bitcoin’s block space is for financial transactions, not JPEGs
  • Argument for: Any valid use of Bitcoin block space is legitimate; censorship resistance applies
  • The debate generated significant fee revenue for Bitcoin miners — making Ordinals a financial positive for network security

Casey Rodarmor’s perspective:

  • Framed Ordinals as a way to bring digital artifacts to the most secure and decentralized blockchain
  • Argued that censoring inscription transactions would undermine Bitcoin’s core promise

History

  • November 2021 — Taproot upgrade to Bitcoin makes large data inscription technically feasible
  • January 2023 — Casey Rodarmor publishes Ordinals protocol; the first inscriptions are created
  • February–March 2023 — Ordinals go viral; Bitcoin fees spike as inscription demand grows; mainstream crypto media coverage
  • March–April 2023 — BRC-20 tokens emerge; fee pressure reaches extremes; Bitcoin blocks fill with inscription data
  • 2023 — Bitcoin NFT marketplaces emerge (Magic Eden, Gamma.io); Ordinals market develops; total inscriptions reach millions
  • 2024 — Ordinals market matures; Runes protocol by Rodarmor replaces BRC-20 for fungible tokens; inscriptions become a permanent part of Bitcoin culture

Common Misconceptions

  • “Ordinals are stored off-chain.” — Ordinal inscription data is stored directly in Bitcoin transactions (in the witness data field), permanently and on-chain. This is what differentiates Ordinals from earlier “Bitcoin NFT” attempts that stored data in other systems.
  • “Ordinals require a layer 2.” — Ordinals are native Bitcoin Layer 1. No Layer 2 or sidechain is required. This is both their appeal (Bitcoin security) and their limitation (no smart contract programmability).

Social Media Sentiment

  • X/Twitter (Bitcoin community): Deeply divided; maximalists hostile; Ordinals enthusiasts energized; the debate is ongoing and heated.
  • X/Twitter (Ethereum NFT community): Ranges from “interesting” to competitive; some Ethereum collectors crossed over to Ordinals; others dismissed the technical limitations.
  • r/Bitcoin: Significantly hostile; most Bitcoin subreddit moderators and users view Ordinals as spam; this view is common among older Bitcoin community members.

Last updated: 2026-04

Related Terms

See Also

  • Bitcoin NFTs — the broader category of NFT-like assets on Bitcoin; Ordinals is the specific protocol; Bitcoin NFTs is the general term
  • On-Chain NFT — the concept Ordinals embodies; all inscription data is stored on-chain, making Ordinals the most on-chain NFT possible (Bitcoin-level security)
  • BRC-20 — the fungible token standard that emerged from Ordinals inscriptions; not created by Rodarmor but used the Ordinals protocol as its foundation

Sources