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.
This is the TXID of the famous Bitcoin Pizza transaction:
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.
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.
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.