TXID

TXID stands for transaction identifier. It is a unique identifier assigned to a digital transaction in a distributed network such as a blockchain. A TXID is typically a cryptographic hash derived from the transaction’s data, and it serves to reference, verify, and track the transaction as it propagates and is recorded in a block. The TXID is usually displayed as a hexadecimal string and remains constant once the transaction is included in the blockchain, allowing users and services to confirm that a payment has been sent or received.

In blockchain contexts, TXIDs are used by wallets, explorers, and node software to fetch transaction details, monitor confirmations, and audit transfers. In Bitcoin, for example, the TXID is the hash of the serialized transaction data. There is also a related identifier known as the wtxid (the hash of the transaction including witness data) used for SegWit transactions; some systems expose one or both values.

TXIDs are publicly visible on the blockchain and facilitate transaction tracking without revealing user identities. However, they do not convey ownership or identity themselves; they only reference specific transactions. Privacy considerations arise because transaction histories can be analyzed to infer behavior and link addresses, even though the addresses themselves do not reveal real-world identities.

If a transaction is replaced or reissued, the resulting transaction will typically have a different TXID. TXIDs enable programmatic access via APIs and blockchain explorers, supporting tasks from balance checks to dispute resolution.