What Is a Bitcoin Transaction ID (TXID)? How to Read One

Key takeaways

• A transaction ID, or TXID, is a 64-character hexadecimal code made by hashing a transaction’s data. It identifies exactly one transaction.
• You can find it in your wallet’s transaction details or in an exchange’s withdrawal record. Paste it into a block explorer to see inputs, outputs, amounts, fee, confirmations and time.
• A TXID is public. It links the addresses involved, but it names nobody and cannot be used to spend coins.
• Sharing a TXID as proof of payment is fine. Sharing a seed phrase or private key never is, and no support request or lookup needs them.
• A TXID alone proves little. Check that the address, the amount and the confirmations match what you expect.

What is a Bitcoin transaction ID?

A Bitcoin transaction ID, or TXID, is a 64-character code that identifies one specific bitcoin transaction. It is also called a transaction hash. Think of it as a tracking number for a payment, except that no company hands it out: it is calculated from the transaction itself.

It is written in hexadecimal, which uses the digits 0 to 9 and the letters a to f. Here is an invented example that follows the format and does not belong to a real payment:

0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef

Sixty-four hexadecimal characters carry 256 bits of information, enough that two transactions will not share an ID in practice. How Does Bitcoin Work? covers the transactions, blocks and miners the ID points to.

How is a TXID created?

A TXID is created by running the transaction’s data through a hash function, which is SHA-256 applied twice. A hash function turns any input into a fixed-length fingerprint, and changing even one detail of the input, such as an amount or an address, produces a completely different result.

That is why a TXID identifies exactly one transaction. The ID exists as soon as your wallet signs the transaction, and nobody assigns or approves it. It is also why a replaced transaction gets a new one: if you raise the fee on a pending payment with replace-by-fee, the new version has a different ID and nodes drop the old one. What Is the Bitcoin Mempool? Why Transactions Wait explains where pending transactions wait.

Where do you find a TXID?

Your wallet shows the TXID in the details of each transaction: open the payment in your history and look for “transaction ID,” “transaction hash” or “TXID,” often with a copy button. For an incoming payment, the wallet usually shows it as soon as it sees the payment on the network.

On an exchange, open the withdrawal history and select the withdrawal. The TXID appears once the exchange has broadcast the payment, and not before. The exchange’s own reference number is a different thing and will not work on a block explorer.

Lightning payments are the exception. They are not recorded on the main chain one by one, so they have no TXID. Only the transactions that open and close a channel do. What Is the Lightning Network? explains why.

How do you look up a transaction on a block explorer?

Open a block explorer, paste the full TXID into its search box and read the page that appears. A block explorer is a website that displays the public ledger, and every confirmed transaction can be found there.

1. Type the explorer’s address yourself or use a bookmark. Lookalike sites and search ads can imitate real ones.
2. Paste the whole TXID, with no spaces added.
3. Read the status, amounts and addresses.
4. Close the page. An explorer never needs your seed phrase, private key or password for a lookup.

If the explorer cannot find the transaction, do not assume the payment failed. The ID may have a typo, the payment may not be broadcast yet, this explorer may not have seen it, a replacement with a new ID may have taken its place, or you may be on a different network. Check all 64 characters and try a second explorer. How Long Does a Bitcoin Transaction Take? explains what to expect while you wait.

What does each part of the page show?

The layout varies by explorer, but most pages show the same pieces.

Part	What it shows
Status	Unconfirmed or confirmed, and the number of confirmations
Block height and time	Which block included the transaction and when
Inputs	The earlier outputs being spent, each with an address and an amount
Outputs	Where the coins go: the payment and usually a change output, each with an address and an amount
Fee	The difference between the inputs and the outputs, often also shown as a rate per unit of data

Take a transaction with two inputs and two outputs. The inputs add up to slightly more than the outputs, and the gap is the fee. One output is the payment and the other is change returning to the sender at a fresh address. The page does not label which is which, so you often infer it. Each output is identified by the TXID plus its position in the list, which is how later transactions point to it. What Is a UTXO? How Bitcoin Tracks Ownership explains this.

“Unconfirmed” means nodes know the transaction but no miner has included it in a block. “Confirmed” means it is in a block, and the count shows how many blocks have been found since, including that one. An unconfirmed payment can still be replaced or dropped, so it is not final.

What does a TXID reveal, and what does it not?

A TXID is public, and anyone who has it can see the amounts, the addresses involved and the time. It names nobody, because an address carries no name. That protection is thinner than it sounds. If one address in the transaction is already tied to a person, through an exchange account, a purchase or a public post, the transaction is tied to that person too. What Is a Bitcoin Address? and Is Bitcoin Private? cover how that linking happens.

A TXID cannot move your coins. Spending needs a signature from the private key, and a TXID is not a key.

Is it safe to share a TXID?

Sharing a TXID is safe for your funds and normal as proof of payment, but it shows the other person the amounts and addresses, so share it only with people who need it.

Never share a seed phrase, a private key or a wallet password with it. A transaction lookup does not need any of them, and anyone who asks is after your coins. What Is a Seed Phrase? explains why.

A TXID alone is also weak evidence, because someone can quote a real one from a different payment. If you are being paid, open it on an explorer and check that the receiving address is yours, the amount is right and enough confirmations have arrived. New to Bitcoin? The Start Here path covers the basics in order.

Which scams involve transaction IDs?

Scams around TXIDs turn a real-looking ID into trust or pressure, and they usually depend on you not checking it yourself.

• Fake proof of payment. A buyer sends a TXID or screenshot that belongs to another payment, goes to a different address or has not confirmed, and asks you to release the goods.
• Fake release fees. A “support agent” asks for your TXID and then wants a fee, or your recovery words, to “unlock” a transaction.
• Fake apps and sites. A look-alike app or page shows an incoming payment that does not exist on the real chain.

Common Bitcoin Scams and How to Spot Them lists more. No legitimate service charges you to release a transaction.

What if an exchange says a withdrawal has no TXID yet?

A withdrawal with no TXID usually means the exchange has not broadcast the payment to the Bitcoin network yet, so there is nothing on the chain to look up. The request may be queued, under a security review, waiting for your email confirmation or grouped with other withdrawals.

Check the withdrawal status and your email, and wait for the processing time the exchange states. If it stays that way beyond that, contact support and quote the exchange’s own withdrawal reference. Some exchanges move coins between their own customers without touching the chain, so there may be no TXID at all. Once one appears, it may show many outputs, because some exchanges batch payments. Find the one with your address, and never pay anyone a fee to “release” a withdrawal.

Does SegWit change how a TXID works?

It changed one detail. Before the Segregated Witness upgrade of 2017, signature data was part of what was hashed, and a third party could re-encode a signature without breaking it, which changed the TXID of an unconfirmed payment while the payment stayed the same. For transactions spending SegWit outputs, signature data is kept apart and left out of the TXID, which closed that route.

Where to go next

• How Long Does a Bitcoin Transaction Take? Confirmations and Fees Explained: what confirmations mean and why waits vary.
• What Is the Bitcoin Mempool? Why Transactions Wait: where unconfirmed payments sit.
• How to Send and Receive Bitcoin Safely: checks to make before and after you send.
• Is Bitcoin Private? What Transactions Reveal: what a public ledger shows about you.