Full Node
A full node is software that independently downloads and validates every block and transaction in the Bitcoin blockchain against all consensus rules. It does not require trust in any third party. Full nodes may optionally prune old block data to save disk space while still validating everything.
How It Works
A Bitcoin full node downloads every block since the genesis block and validates each transaction and block against the complete set of consensus rules. This includes checking that no bitcoin is double-spent, that signatures are valid, that the block reward is correct, and that the difficulty target is properly enforced. If any rule is violated, the node rejects the block entirely, regardless of how many other nodes accepted it.
Running a full node requires modest resources — a reasonably modern computer with several hundred gigabytes of storage and a decent internet connection. Software like Bitcoin Core, the reference implementation, handles everything automatically. Once synced, your node stays current by validating new blocks as they arrive. You can also prune old block data if storage is a concern, while still validating everything.
For anyone practicing self-custody, running a full node is not optional — it is essential. When you connect your wallet to your own node, you eliminate trust in third parties. You verify your own balances, broadcast your own transactions, and enforce the rules you agreed to. This is what "don't trust, verify" actually means in practice.
Key Points
- Validates every transaction and block against all consensus rules independently
- Eliminates reliance on third-party services for balance and transaction verification
- Requires only modest hardware — any modern computer can run one
- Essential for true self-custody and privacy
- Enforces the rules of Bitcoin as you understand them — no delegation of trust