What are transaction hashes?

What are transaction hashes?

A transaction hash is often called a “tx hash” or “transaction ID.” It is a unique identifier given to a blockchain transaction once it is created and broadcasted to the network.

Here’s a breakdown:

  • 🔹 Definition:
    A transaction hash is essentially the digital fingerprint of a blockchain transaction. It’s generated using a cryptographic hash function (like SHA-256 in Bitcoin or Keccak-256 in Ethereum).
  • 🔹 Format:
    It’s usually a long string of letters and numbers (hexadecimal), for example:0x5e3b5f9f7c9c9c77e99e3f0d5e6a6f3f4b2a1b8d7c3e1f2a6b9f0d9c7a8b5f2
  • 🔹 Purpose:
    • Let anyone track and verify the transaction on a blockchain explorer.
    • Acts like a receipt number—proof that the transaction exists.
    • Ensures immutability: even if transaction details are public, no two different transactions can have the same hash.
  • 🔹 Example in use:
    If you send Bitcoin or Ethereum to someone, the wallet or exchange will give you the transaction hash. You can paste that hash into a blockchain explorer (like etherscan.io for Ethereum or blockchain.com for Bitcoin) to check:
    • The amount sent
    • Sender and receiver addresses
    • Network fees
    • Block confirmation status

👉 In short: A transaction hash = unique ID + receipt for your blockchain transaction.

Here’s a step-by-step on how to look up a real transaction hash using a blockchain explorer (Ethereum / Etherscan example). You can use similar steps for other chains (Bitcoin, BSC, etc.).

🔍 Steps to Look Up a Transaction Hash (using Etherscan)

  1. Get the transaction hash (tx hash / tx ID).
    This is the string you got after sending the Ethereum (or token) transaction. It looks like a long hex string starting with 0x….
  2. Go to Etherscan.
    Visit etherscan.io.
  3. Paste the transaction hash into the search bar.
    On the homepage, there’s a search input. Paste the tx hash there and hit Enter/click search.
  4. View transaction details.
    After searching, you’ll land on a “Transaction Details” page. Here are some of the key fields you’ll see:
    • Status—whether it was successful, failed, or is pending.
    • Block—the block number that includes this transaction.
    • Timestamp—date & time when the block was mined.
    • From/To—sender and receiver addresses.
    • Value—the amount of ETH (or token) transferred.
    • Gas/Fee/Gas Price—how much gas was used, how much was paid, etc.
    • Input Data / Token Transfers—If interacting with a smart contract or sending tokens, you may see extra data / token movements.
  5. Interpret the result.
    • If “Status = Success,” then the transaction was executed.
    • If “Pending,” it’s still waiting to be mined.
    • If “Failed,” something went wrong (for example, not enough gas, a revert in a smart contract, etc.).
    • You can see how much fee was paid, which addresses participated, and more.