A computer that downloads, validates, and stores the complete Bitcoin blockchain and independently enforces all consensus rules. Full nodes are the backbone of Bitcoin's decentralization, ensuring no one can cheat the system.
A computer that downloads, validates, and stores the complete Bitcoin blockchain and independently enforces all consensus rules. Full nodes are the backbone of Bitcoin's decentralization, ensuring no one can cheat the system.
A full node is the ultimate authority in Bitcoin's trust model. It independently verifies every transaction and every block against the consensus rules — checking signatures, confirming no double-spends, verifying the proof of work, and enforcing the 21 million supply cap. Unlike lightweight wallets that trust third parties, a full node trusts no one. If a miner produces an invalid block, your full node will reject it regardless of how much hash power backs it.
Running a full node requires downloading the entire blockchain (currently over 600 GB) and staying synced with new blocks. While this demands significant storage, the actual computational requirements are modest — a Raspberry Pi or an old laptop can run a full node. Software like Bitcoin Core, the reference implementation, is free and open source. Several plug-and-play node products also exist for non-technical users.
The network's health depends on having thousands of independent full nodes distributed globally. Each node is a vote for the consensus rules — if a proposed protocol change is contentious, nodes can simply refuse to adopt it. This is what happened during the 2017 block size wars: despite significant miner support for larger blocks, the majority of full nodes refused the change, preserving the existing rules. Full nodes give individual users sovereignty over their own verification of Bitcoin's rules.
Running a full node gives you the highest level of security and privacy. You verify your own transactions without trusting any third party. You also contribute to network decentralization and get a direct vote on consensus rules. If you hold significant Bitcoin, running a node is the most sovereign way to interact with the network.
You need about 1 TB of storage (to accommodate growth), 2 GB of RAM, and a stable internet connection. A Raspberry Pi 4 with an external SSD works well and costs under $200. The initial blockchain sync takes several hours to days depending on your hardware, but after that the node stays current with minimal resources.
All mining nodes are full nodes, but not all full nodes mine. A full node validates and relays transactions and blocks. A mining node does all of that plus actively competes to create new blocks using specialized hardware. You can run a full node to verify and support the network without mining.