A full node is a program that fully validates transactions and blocks. Almost all full nodes also help the network by accepting transactions and blocks from other full nodes, validating those transactions and blocks, and then relaying them to further full nodes.
Most full nodes also serve lightweight clients by allowing them to transmit their transactions to the network and by notifying them when a transaction affects their wallet.
Many people and organizations volunteer to run full nodes using spare computing and bandwidth resources—but more volunteers are needed to allow Bitcoin to continue to grow. This document describes how you can help and what helping will cost you.
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Costs And Warnings Running a Bitcoin full node comes with certain costs and can expose you to certain risks. Special Cases Miners, businesses, and privacy-conscious users rely on particular behavior from the full nodes they use, so they will often run their own full nodes and take special safety precautions.
This document does not cover those precautions—it only describes running a full node to help support the Bitcoin network in general. Please seek out assistance in the community if you need help setting up your full node correctly to handle high-value and privacy-sensitive tasks. Do your own diligence to ensure who you get help from is ethical, reputable and qualified to assist you. Please see the securing your wallet page for more information.
Minimum Requirements Bitcoin Core full nodes have certain requirements. Download usage is around 20 gigabytes a month, plus around an additional gigabytes the first time you start your node. You can do other things with your computer while running a full node. More hours would be better, and best of all would be if you can run your node continuously.