Bitcoin Developers Release Major Update on Testnet, What Changed?

Bitcoin (BTC) developers have announced the release of v31.0rc4 for testing. As highlighted by Bitcoin Core Project on X, this major release follows v30.2 and comes with binaries and draft notes available for review by developers, node operators and testers.

New privacy enhancements through Tor and I2P networks

The announcement targets Bitcoin researchers, miners and wallet infrastructure providers as a major change has been introduced in the cluster mempool design. For clarity, the mempool is like a waiting room where transactions sit before miners include them in blocks. In this redesign, there is improvement in transaction selection for blocks, fee efficiency and the handling of complex transaction packages. Rather than impose limits, the new system organizes transactions into clusters. It comes with a default limit of 64 transactions per cluster and 101 kB size. The idea is to help the node make better decisions when prioritizing transactions by fees. Additionally, the update allows a user to replace a pending transaction with a higher-fee version. This will ensure that a replacement improves the mempool’s overall fee structure.

A new release candidate of Bitcoin Core, v31.0rc4, is available for testing. This is a new major release, and follows v30.2. Work-in-progress release notes are here: Binaries are available here:

— Bitcoin Core Project (@bitcoincoreorg) April 11, 2026 The Bitcoin node software v31 also has improved privacy features, better fee estimation and performance upgrades. On the privacy front, transactions can only be broadcast through Tor or I2P networks. The advantage of this over the previous version is that a user’s IP address is hidden, and multiple transactions cannot easily be linked together. It will improve privacy for Bitcoin users running their own node. Meanwhile, to help nodes sync faster and validate blocks faster, the default database cache was increased from 450 MB to 1,024 MB. However, this is only applicable on systems with at least 4 GB RAM. There are several outdated options that were removed, including paytxfee, maxorphantx and the old tor network label. These cleanups simplify the software and reduce user mistakes.

Testing phase begins ahead of final release

Overall, the Bitcoin node software v31 is meant to handle complex transaction chains better and improve privacy. The node performance will be better as blocks get validated faster with more accurate fee estimation. The developers are hoping that node operators, miners and infrastructure providers will put the new version to the test before its final release. This is to ensure seamless functionality when released. In another development, JAN3 CEO Samson Mow has dismissed concerns around quantum computer threats to Bitcoin. Mow emphasized that researchers are already ahead of the quantum computer threats with solutions to safeguard Bitcoin’s transactions.