Transaction Hash (TXID)

A transaction hash, often called a TXID, is a unique identifier generated by running a transaction's data through a cryptographic hash function (see Kaavon's "Hash Function" glossary definition), producing a fixed-length string that serves as that transaction's permanent, unique fingerprint on the blockchain. Because even a tiny change to any part of a transaction's data produces a completely different hash, a TXID reliably identifies one specific transaction and no other.

A transaction hash is the standard reference used to look up a specific transaction on a block explorer (see Kaavon's dedicated glossary entry), confirm it was successfully included in a block, and verify its details — such as the amount sent, the sender and recipient addresses, and the number of confirmations it's received. Sharing a transaction hash with a counterparty, such as a merchant or customer support team, is a common way to prove a specific payment was made without needing to reveal any other wallet information.