Verifying and Exploring Your Transaction

What You’ll Learn

• How to read your transaction in a block explorer
• What confirmations mean and how many you need
• Where to go next: multisig, timelocks, and Taproot

Reading Your Transaction in an Explorer

Once broadcast, you can look up your transaction by its txid in any block explorer. Here is what you’ll see and what each field means:

Transaction ID:    a1b2c3d4e5f6...
Status:            Confirmed (Block #840,000)
Confirmations:     6
Size:              222 bytes / 141 vBytes
Fee:               1,410 sats (10.0 sat/vB)

Inputs:
  ← bc1q...sender  0.005 BTC  (from txid:abc123..., vout:0)

Outputs:
  → bc1q...recipient  0.003 BTC
  → bc1q...change     0.001959 BTC

Every field maps to something you built by hand:

• Inputs — The UTXOs you referenced in Step 3
• Outputs — The new UTXOs you created in Step 4
• Fee — The difference you calculated in Step 5
• Size/vBytes — The serialized data from Step 6

Understanding Confirmations

A confirmation means your transaction is included in a block, and additional blocks have been built on top of it.

Confirmations	Meaning	Typical Use
0	In the mempool (unconfirmed)	Not safe to trust
1	Included in the latest block	Small purchases
3	Two blocks built on top	Moderate-value transfers
6	Five blocks deep	Industry standard for finality
100+	Deeply buried	Required for spending coinbase rewards

Each additional confirmation makes reversal exponentially harder. To undo a transaction with 6 confirmations, an attacker would need to re-mine 6 blocks faster than the rest of the network — requiring an enormous share of the global hashrate.

For most purposes, 6 confirmations (~1 hour) is considered final.

Verifying With Your Own Node

Trusting a block explorer means trusting a third party. To verify independently:

# Decode and inspect the raw transaction
bitcoin-cli getrawtransaction "txid" true

# Check confirmation count
bitcoin-cli gettxout "txid" 0

The gettxout command checks the UTXO set directly — if it returns data for your output, the UTXO exists and is unspent. If it returns nothing, the output either doesn’t exist or has already been spent.

Running a full node is the only way to verify transactions without trusting anyone. This is what “don’t trust, verify” means in practice.

What You’ve Built

Over these 10 steps, you constructed a Bitcoin transaction from scratch:

1. Selected a UTXO to spend
2. Built an input pointing to that UTXO
3. Created outputs for the recipient and change
4. Calculated an appropriate fee
5. Serialized everything into raw hex
6. Signed the transaction with your private key
7. Added SegWit witness data
8. Broadcast the transaction to the network
9. Verified confirmation on the blockchain

You now understand every byte in a Bitcoin transaction. Most wallet software does all of this in milliseconds behind a “Send” button — but knowing what happens underneath changes how you think about the protocol.

Where to Go Next

The transaction you built is a simple single-signature payment. Bitcoin’s scripting system enables far more:

Multisig Transactions

Require multiple private keys to authorize spending (e.g., 2-of-3). Used for corporate treasuries, shared custody, and eliminating single points of failure. See Multisig.

Timelocks

Lock bitcoin so it cannot be spent until a certain time or block height. Enables inheritance planning, escrow, and payment channels. Two opcodes: OP_CHECKLOCKTIMEVERIFY (absolute) and OP_CHECKSEQUENCEVERIFY (relative).

Taproot (BIP340/341/342)

Activated in November 2021, Taproot uses Schnorr signatures and MAST (Merklized Alternative Script Trees) to make complex transactions look identical to simple ones on the blockchain. This improves privacy, reduces fees for complex scripts, and enables more sophisticated smart contracts.

Lightning Network

A Layer 2 payment network that enables instant, low-fee Bitcoin transactions by creating payment channels built on Bitcoin transactions — the same kind you just learned to construct. See Lightning Network.

Course Complete

You have finished the “Build Your First Transaction” course. You’ve gone from conceptual understanding to byte-level knowledge of how Bitcoin transactions work. Every other Bitcoin technology — from Lightning to Taproot to sidechains — is built on this foundation.

The best way to solidify this knowledge: build a real transaction. Use Bitcoin’s testnet (or signet) to construct, sign, and broadcast a transaction using the principles from this course. No real bitcoin at risk, full learning payoff.