UTXO (Unspent Transaction Output)
Protocol
Unspent Transaction Output model used by Bitcoin.
The UTXO model tracks Bitcoin as a set of spendable outputs rather than balances in accounts. When you receive funds, you get one or more UTXOs. When you send, your wallet chooses UTXOs as inputs, creates outputs to the recipient and to your change address, and signs the transaction. Understanding UTXOs helps with privacy and fees. Consolidate small UTXOs when fees are low, and let your wallet send change to a fresh address. If you run your own node, you can verify your UTXOs directly for greater trust.
Frequently asked questions
What is a UTXO?
A spendable output from a past transaction. Your wallet builds new transactions by selecting UTXOs as inputs.Why does UTXO selection matter?
It affects privacy, fees, and change. Good selection reduces dust and keeps future fees lower.Where do I see my UTXOs?
Advanced wallets and explorers can list them. Most wallets manage them for you by default.