// GLOSSARY -- BLOCKCHAIN & CRYPTO FUNDAMENTALS

What is Transaction Hash?

1 min read Updated

A transaction hash (txHash) is a unique identifier generated by hashing a transaction's contents — serving as the receipt and lookup key for any blockchain transaction.

WHY IT MATTERS

Every blockchain transaction gets a unique hash — a 66-character hexadecimal string on Ethereum. This hash is the transaction's permanent identity, used to look up status, confirm inclusion in a block, and verify execution details.

Transaction hashes are generated deterministically from the transaction's contents (sender, recipient, value, data, nonce, gas parameters, signature). This means the hash is known immediately after signing, before the transaction is even mined.

For developers and agents, transaction hashes are essential for tracking: submit a transaction, get the hash, poll for confirmation, verify success or failure. They're the primary reference in debugging and audit trails.

FREQUENTLY ASKED QUESTIONS

Where can I look up a transaction hash?
Block explorers like Etherscan (Ethereum), Solscan (Solana), or Basescan (Base). Paste the hash to see full transaction details, status, and gas costs.
Can two transactions have the same hash?
Practically impossible. Cryptographic hash functions are collision-resistant — finding two different transactions with the same hash is computationally infeasible.
What does a pending transaction hash mean?
The transaction has been submitted to the network but not yet included in a block. It may be waiting in the mempool for validator inclusion.

FURTHER READING

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