What is Bitcoin Core?

Bitcoin Core is free, open-source software that runs a full node: it downloads every block, checks it against Bitcoin's rules and passes valid payments on to other nodes. It also has a wallet and a desktop app. The project calls it “a direct descendant” of the program Satoshi Nakamoto released in 2009.

No company owns it. Anyone can propose a change on GitHub, and other contributors review and test it. A few maintainers can merge changes, a job the project describes as “janitorial”: merging what contributors agree on. Running it is voluntary, so a new version only changes anything for the people who install it.

Bitcoin Core aims for a major release every six or seven months, such as 31.0 in April 2026 and 32.0 on 27 October 2026, with maintenance releases such as 32.1 for fixes in between. The latest three major versions get fixes. A change to the consensus rules always ships first in a maintenance release.

Its defaults shape what most nodes relay, so changes to them get argued over: 30.0, in October 2025, raised the limit on OP_RETURNOP_RETURNA payment output that stores data instead of paying someone. It can never be spent, so nodes don't track it as spendable. data from 83 bytes to 100,000. On 8 November 2026, 18,480 of the 20,645 reachable nodes Bitnodes counted ran Bitcoin Core.