Inscription

Inscriptions use an envelope of script data placed inside a Taproot transaction's witness, the part of the transaction that SegWit discounts in fees. The content can be any file type and is stored entirely on the Bitcoin blockchain. Ordinals software then assigns the inscription to the first satoshi of the output, and whoever holds that satoshi owns the inscription. Each one gets a sequential inscription number.

Since the first inscriptions appeared in early 2023, tens of millions have been created: images and generative art collections, text, HTML and the JSON files behind BRC-20 tokens. Collectors value low inscription numbers and fully on-chain storage, which avoids the broken links that affect many NFTs on other chains. Inscription waves have repeatedly pushed Bitcoin fees and miner revenue higher.

Inscriptions are a convention recognised by indexers, not by Bitcoin nodes, so wallets that are unaware of them can accidentally spend inscribed satoshis as fees. The practice is controversial among Bitcoin users who see it as spam competing with payments for blockspace, a debate that fed the 2025 discussion over data-carrying limits.