OP_RETURN
Protocol● Common

A Bitcoin script opcode that marks an output as provably unspendable, allowing embedding of up to 80 bytes of arbitrary data. Used for timestamping, proof-of-existence, token protocols, and metadata without bloating the UTXO set.

Technical Notes

Output is immediately prunable from UTXO set (unspendable). Pre-2014: data embedded in fake addresses bloated UTXO set. Standard relay: one OP_RETURN per tx, 80 bytes max. Used by: OpenTimestamps, Omni Layer, colored coins, commitments.

Metadata

Visibility: Public
Created:1/3/2026by System

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