Mempool at mempool.space lets you look up a Bitcoin payment and understand its confirmation status, receiving outputs, and network fee. This guide walks through a transaction lookup first, then explains the information you see and how to explore addresses and blocks.

The instructions apply to Bitcoin Mainnet, the network used for real bitcoin payments. They do not apply to Ethereum, tokens on other networks, or individual Lightning payments.

Choose a transaction or address lookup

Use a transaction lookup when you have the payment's complete identifier. If you only know the receiving address, use the address-lookup procedure below to find the payment in its history, then open its transaction details. Use the full public address from your wallet or the original payment instructions, rather than an unfamiliar entry in a transaction history.

Look up your Bitcoin transaction

Have the complete transaction ID ready. It identifies one transaction and is different from a receiving address or an exchange's internal withdrawal reference. In the BitBoxApp, open the relevant Bitcoin account and its transaction details, then copy the full Transaction ID. The app may shorten the value displayed on screen, so use the copy control rather than copying only the visible characters. See How to view transaction details in the BitBoxApp if you need help finding it.

Searching a public explorer shares the identifier you look up with that service and may expose your IP address. You do not need to connect your BitBox, unlock a wallet, or sign anything to inspect a public transaction.

1. Open mempool.space. Check that the network selector beside the Mempool logo is set to Mainnet. If it shows a test network, use the selector to choose Mainnet.
2. Paste the complete transaction ID into the search field in the top navigation bar and press Enter or select the search button. Mempool opens the matching Transaction page if it can find the transaction.
3. Compare the transaction ID at the top of the result with the one from your wallet or sending service. Then check the confirmation state and the receiving output as described below.

The lookup is complete when you have matched the transaction ID, identified the intended receiving output and amount, and established whether the transaction is unconfirmed or included in a block. Finding the page alone does not establish that the intended payment succeeded.

Understand confirmations and the estimated wait

Unconfirmed means Mempool has seen the transaction but it is not currently included in the blockchain. The transaction may be waiting in nodes' temporary collections of unconfirmed transactions, called mempools. There is no single shared mempool: each node has its own view.

When the transaction is included in a block, it has its first confirmation. Each block added after that gives it another confirmation. More confirmations make a transaction harder to reverse through a change to the recent chain history, known as a reorganization.

An ETA or expected block position is an estimate. New transactions, changing fee competition, and the unpredictable time of the next block can change it. Bitcoin targets an average block interval of about ten minutes; it does not promise a block every ten minutes.

The BitBoxApp marks a Bitcoin transaction Complete after six confirmations. An exchange or another recipient may have its own crediting requirements. If your transaction is delayed or the app and explorer disagree, use Why is my Bitcoin transaction pending? for the next steps.

Read the inputs and outputs

Scroll to Inputs & Outputs on the transaction page. Bitcoin spends amounts created by earlier transactions and creates new amounts assigned to receiving conditions, usually represented by addresses. These spendable amounts are called unspent transaction outputs, or UTXOs.

• Inputs identify earlier outputs being spent. Their total can be greater than the amount you intended to pay because each selected output is spent in full.
• Outputs show where the transaction assigns the bitcoin. A payment can include an output for the recipient and a change output returning the remainder to the sender's wallet.
• The fee is the difference between the total input amount and the total output amount. It is not another receiving output.

Find the output with the full receiving address agreed for the payment and compare its amount. Do not use the sum of all outputs as the amount paid to one recipient.

Example: a payment with change

Suppose your wallet spends one output worth 0.01000000 BTC to pay someone 0.00300000 BTC, with a fee of 0.00001000 BTC. These hypothetical figures would produce:

The input is larger than the payment, but the wallet has not paid the entire input to the recipient. It has created change, much like paying with a larger banknote and receiving the remainder.

Not every transaction has this shape. There may be several inputs, many recipients, or no change output. An unfamiliar address is not automatically yours, and an explorer cannot reliably establish wallet ownership from the layout alone. If the outputs do not match what you expected, compare them with your wallet's record before drawing a conclusion.

Distinguish the fee from the fee rate

Fee is the total network fee for the whole transaction, often shown in satoshis, or sats. One bitcoin equals 100,000,000 sats. If you received a payment from an exchange or another wallet, the explorer's fee belongs to that whole transaction; it is not necessarily the exchange withdrawal charge or a fee you paid yourself.

Fee rate, shown in sat/vB, relates the fee to the transaction's virtual size. It helps compare the fees offered by transactions competing for block space. A larger payment amount does not automatically require a larger fee: transaction structure and network conditions matter.

For a simple hypothetical transaction with a virtual size of 200 vB and a fee of 1,000 sats, the fee rate is 5 sat/vB. Two transactions can pay the same total fee but have different fee rates if their sizes differ.

Mempool may also show an effective fee rate when related transactions affect their combined mining incentive. It also accounts for adjusted virtual size where relevant. You do not need to change these technical values to inspect a payment. For the underlying fee models, see What are blockchain network fees?.

Explore an address or an earlier transaction

An address lookup helps you inspect payments involving one Bitcoin address, including when the sender has not supplied a transaction ID. You can use it without making another payment or connecting your wallet.

1. Open mempool.space and check that the network selector shows Mainnet.
2. Paste the complete public Bitcoin address into the top search field and press Enter. The address page opens if the address is recognized. Compare its full address with the one you intended to inspect.
3. Review its balance and transaction history. To find an expected receipt, compare the receiving amount and approximate time, then select the matching transaction ID to open its details.
4. On the transaction page, check the output to that address and the confirmation state. If several entries could match, ask the sender for the exact transaction ID rather than guessing.

The address balance describes what remains associated with that address, while its history can include amounts already spent. For example, an address may have received 0.01 BTC and later had that output spent. A zero balance today does not mean the original receipt failed. Some of the spent amount may have returned as change to another address in the same wallet; use your wallet's account history to understand the complete result.

You can also select an address under Inputs & Outputs to view its history. This helps follow related activity, but it does not prove who controls the address or why a transfer occurred. A Bitcoin wallet commonly uses many receiving and change addresses, so one address's balance is not the whole wallet balance.

Read the homepage's blocks and fee estimates

Return to Mempool's homepage to see current network conditions. Projected blocks group unconfirmed transactions into possible future blocks. Mined blocks have block heights, such as a numbered entry for a block already found. Their positions and colors can vary with display settings, so distinguish them by their information rather than color alone.

Select a projected block to inspect the transactions Mempool currently expects could fit there. Select a numbered mined block to see its block details and included transactions. You can also search for a block height or block hash in the top search field.

Under Transaction Fees, the priority options suggest fee rates for different levels of urgency. They are guidance for preparing a transaction, not reserved places or guaranteed confirmation times. The explorer's minimum fee or memory-usage figures describe its node observations and policies; they do not establish that a transaction has been canceled across the network.

If the result is missing or the transaction was replaced

If Mempool cannot find the transaction, first check Mainnet, compare the complete transaction ID, and reload the page. If an exchange or another wallet is sending it, ask that service whether it has broadcast the payment and request the blockchain transaction ID.

If Mempool shows that a transaction was replaced, follow the replacement link and inspect the new transaction's outputs and confirmation state. A replacement has a different transaction ID and may change the payment's result; do not assume the original recipient was paid without checking.

For a transaction shown in the BitBoxApp that remains missing or inconsistent after these checks, follow the support path in Why is my Bitcoin transaction pending?. An explorer displays information; it cannot force a confirmation or reverse a payment. Other Bitcoin explorers, such as Blockstream Explorer, can provide another view, but their controls and observations may differ.