Transaction ID (TXID)

Intermediate

What Is A Transaction ID?

A transaction ID (TXID), or transaction hash, can be thought of as an identification number that labels each transaction on the blockchain. It is a unique string of characters that can be verified and added to the blockchain.

When a transaction gets added to the blockchain, it’s assigned a unique transaction ID. The transaction ID is generated by applying a hash function to the transaction details, including the sender's address, the receiver's address, and the amount of cryptocurrency being sent.

Depending on the blockchain used, you’ll be able to find the transaction on a block explorer by searching for the transaction ID. Transaction IDs are useful for transaction verification, record keeping, and troubleshooting.

Examples of Transaction ID

The TXID of the first-ever Bitcoin transaction

This is the TXID of the first-ever Bitcoin transaction sent by Satoshi Nakamoto to Hal Finney:

F4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16

The TXID of the Bitcoin Pizza transaction

This is the TXID of the famous Bitcoin Pizza transaction:

Cca7507897abc89628f450e8b1e0c6fca4ec3f7b34cccf55f3f531c659ff4d79

Bitcoin uses the SHA-256 (Secure Hash Algorithm 256-bit) cryptographic hash function for generating transaction IDs. This function takes in transaction data as input and outputs a 256-bit hash, which is represented as a 64-character long hexadecimal number.

You can look up these transactions yourself by copying the TXIDs into a Bitcoin block explorer, such as blockchain.com or blockchair.com.

Where To Find Your Transaction ID?

Transaction IDs are accessible through blockchain explorers, rendering all associated transaction details visible publicly. This transparency means that anyone can inspect all information tied to a specific transaction or address. While these IDs don’t explicitly disclose the real-world identities of the sender and recipient, there are methods that can potentially establish these connections.

Where to find transaction IDs on centralized exchanges

When you withdraw cryptocurrency from a centralized exchange (CEX) like Binance, the platform will show you the TXID of your withdrawal transaction. On Binance, you can find this on your Transaction History page. If you click on a TXID for a given withdrawal, it’ll take you to the relevant transaction in that blockchain’s block explorer.

If you send funds to the wrong address (or blockchain), the TXID in your withdrawal history is essential to start looking into whether you can recover your funds. Even so, recovery isn’t guaranteed and it’s best to contact support on the platform that you’re sending your funds to.