📮 Bitcoin Stamps Bitcoin Stamps
Bitcoin Stamps embed an image or token directly into Bitcoin's transaction outputs — the part every node must always keep. Because that data can't be pruned away, a stamped file stays on the chain permanently. The fungible token standard built on it is called SRC-20.
📦 The simple version — data that nodes can't throw away
To stamp an image, the file is shrunk to a tiny size, converted into a long line of text (a Base64 string), and labelled with the prefix STAMP:. That text is then tucked inside the transaction's outputs — specifically a bare multisig output, where the slots that normally hold signing keys instead hold the encoded file. Outputs live in the part of Bitcoin called the UTXO set (unspent transaction outputs), and every full node has to keep the whole UTXO set to know who owns what. That is the trick: because no node can safely delete it, the stamped data sticks around for good.
🆚 Stamps vs Ordinals — where the data lives
Both let you put pictures and tokens on Bitcoin, but they hide the data in different rooms of a transaction. Ordinals store theirs in the witness section, which a node can in principle prune later. Stamps store theirs in the outputs that every node must keep. So the choice is permanence versus price and size.
| 📮 Bitcoin Stamps | 🔢 Ordinals | |
|---|---|---|
| Where data lives | Transaction outputs (UTXO set) | Witness section |
| Can it be pruned? | No — nodes keep it | In principle, yes |
| Cost to mint | Higher | Lower |
| Typical size | Tiny image (often ~24x24 px) | Larger files allowed |
📌 Same goal, opposite trade-off: Stamps pay more for permanence, Ordinals pay less but accept that the data could theoretically be dropped.
🪙 SRC-20 and SRC-721 — tokens built on Stamps
Once you can write data into Bitcoin this way, you can write more than pictures. SRC-20 is the fungible-token standard built on Stamps — Bitcoin's output-based answer to BRC-20-style tokens, where the difference is again that the data lives in outputs rather than the witness. SRC-721 is the matching standard for NFTs, using layered images and small colour palettes to keep file sizes down.
🧭 Where it came from
Bitcoin Stamps were created by software engineer Mike In Space and first built on top of the Counterparty protocol, which has existed since 2014. Around block height 796,000 (roughly July 2023), SRC-20 tokens stopped needing Counterparty and began writing to the chain more directly. Stamps arrived as part of the 2023 wave of putting art and tokens onto Bitcoin itself, alongside Ordinals.
🚨 Things beginners should know
- 🔒 Permanence is the whole point — Once stamped, the data sits in the always-kept UTXO set and is meant to never disappear
- 💸 Minting costs more — That permanence is paid for in higher fees than an Ordinal of similar content
- 🖼️ Images stay tiny — Classic Stamps favour very small files, often around 24x24 pixels
- ⚠️ New and experimental — This is a young 2023-era corner of Bitcoin; only explore with money you can afford to lose
❓ FAQ
- Are Bitcoin Stamps just Bitcoin's version of Ordinals?
- No. They store data in different places. Ordinals put data in the witness part of a transaction, which a node can in principle drop. Stamps put data in the transaction outputs (the UTXO set), which every node has to keep. That is what makes Stamps un-prunable and permanent, while costing more and limiting the image size.
- What is SRC-20?
- SRC-20 is the fungible-token standard built on Bitcoin Stamps. It plays a similar role to BRC-20, but the token data lives inside Bitcoin's transaction outputs instead of the witness section. SRC-721 is the matching standard for layered-image NFTs.
- Why are Bitcoin Stamps more expensive than Ordinals?
- Stamps store data in transaction outputs that every node keeps forever, and that permanence is paid for in higher minting fees. To keep the cost manageable, classic Stamps stick to very small images, commonly around 24x24 pixels.