Bitcoin Core

Bitcoin Core is the program most people use to run a full nodeGlossaryFull nodeA node that checks every block and every transaction itself against all the consensus rules. If you run a full node, you don’t have to trust anyone to know whether a payment is valid.In the glossary →×. It is a direct descendant of the first Bitcoin software released by Satoshi NakamotoGlossarySatoshi NakamotoPseudonym of the person or group who invented Bitcoin. Satoshi published the whitepaper in 2008, launched the network in 2009 and withdrew in 2011. Who is behind the name remains unknown to this day.In the glossary →× and is developed by an open community.^[1]

What the software does

Bitcoin Core downloads all blocks and transactions from the network and fully verifies them. It comes with a wallet and a graphical interface. The code is public and released under the free MIT licence.^[2]

Who decides on changes?

Anyone can propose and review changes. But every node operator has to install them – nobody can force you to update.

Version 30.0, for example, was controversial: in October 2025 it raised the default limit for extra data (OP_RETURNGlossaryOP_RETURNA command in Bitcoin’s scripting language that marks a transaction output as provably unspendable. It lets data be written into the blockchain. How much of it nodes should relay has been hotly disputed since 2025.In the glossary →×) from 83 to 100,000 bytes. This only affects which transactions a node passes on, not the consensus rules.^[3] Of the publicly reachable nodes, just over 83% recently ran Bitcoin Core and just under 17% the alternative Bitcoin Knots (as of September 2026).^[4] The dispute is explained in Forks & controversies.

If you want to use it

• Only download it from bitcoincore.org and, if you can, verify the signatures.
• As a wallet, it isn’t very convenient for beginners. You can also run it purely as a node and connect a different wallet to it.
• Hardware and storage: see Nodes & decentralisation.