Full node
A full node is a Bitcoin client that downloads the entire blockchain, independently verifies all consensus rules and doesn't have to trust any third party.
A full node (Bitcoin Core, Knots, Umbrel) validates every transaction and block against consensus rules: signature correctness, script validity, no double spends, correct block structure. The decentralised heart of Bitcoin: the more full nodes, the more robust the network. Roughly 15,000–20,000 publicly reachable full nodes run worldwide, plus thousands of non-listening ones.
Example
Someone receives 0.1 BTC. Their full node checks: does the UTXO exist, is the signature valid, does the script follow the rules, does it fit the current chain? Only then accept — independent of banks or exchanges.
Frequently asked questions
Why run a full node?
Sovereignty: you trust no one. You verify your own transactions, help the network and can operate more privately (no SPV leaks). Running on a Raspberry Pi costs under 300 euro one-off.
Disk requirements?
Full chain: ~650 GB (2026), growing ~50 GB/year. Pruned node: 10–20 GB (keeps validation, discards old blocks). SSD strongly recommended.
Related terms
Further reading
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