Bitcoin Core 28.0 Release: Key Features and Upgrade Guide

Bitcoin Core 28.0 introduces significant enhancements, including Testnet4 support, JSON-RPC 2.0 compliance, and improved mempool policies. This guide covers everything you need to know about upgrading and leveraging new functionalities.

How to Download and Install Bitcoin Core 28.0

👉 Download Bitcoin Core 28.0 binaries or access the source code on GitHub.

Upgrade Process

Shut down older Bitcoin Core versions completely
Replace files:
- Windows: Run installer
- macOS: Copy /Applications/Bitcoin-Qt
- Linux: Replace bitcoind/bitcoin-qt

# macOS self-signing required:
cd /path/to/bitcoin-28.0/bin
xattr -d com.apple.quarantine bitcoin-cli bitcoin-qt bitcoind
codesign -s - bitcoin-cli bitcoin-qt bitcoind

Key Features in Bitcoin Core 28.0

1. Testnet4/BIP94 Support

Enabled via -testnet4 flag
Backward-compatible with Testnet3
Implements BIP 94 specifications

2. Windows Data Directory Migration

Default location changed to:
C:\Users\Username\AppData\Local\Bitcoin
(Legacy path still detected for compatibility)

3. JSON-RPC 2.0 Compliance

Strict adherence to JSON-RPC spec
Clients may require updates (details)

4. Network and P2P Improvements

UNIX socket support for proxy connections
Enhanced whitelist controls (in/out flags)
Limited package relay for low-fee transactions

Mempool Policy Updates

Feature	Description	PR Reference
TRUC Transactions	Version 3 TXs treated as standard	#29496
P2A Outputs	New witness type for key-less anchors	#30352
Package RBF	Limited to cluster size ≤ 2	#28984
Full-RBF Default	Enabled (`mempoolfullrbf=1`)	#30493

Wallet Enhancements

Mempool conflict detection: Visible in gettransaction outputs
New RPCs:
- createwalletdescriptor for descriptor upgrades
- gethdkeys lists all BIP32 HD keys
- sendall now spends unconfirmed change
Fee bumping: No longer restricted to 5 sat/vb increments

👉 Explore advanced wallet features

FAQ

Q: How do I report bugs?
A: Use the GitHub issue tracker

Q: What are the system requirements?
A: Linux Kernel 3.17+, macOS 11.0+, Windows 7+. Unsupported systems not recommended

Q: Is libbitcoinconsensus still available?
A: No - removed after deprecation in v27.0

Q: How are UTXO sets handled now?
A: New format for dumptxoutset/loadtxoutset - old formats incompatible

Q: What’s the minimum compiler version?
A: GCC 11.1+ or Clang 16.0+ required

Build System Changes

Glibc ≥2.31 required (RHEL 8/Ubuntu 18.04 no longer supported)
Boost.Process replaced with embedded cpp-subprocess
Block files now XOR-encrypted by default

Credits

Special thanks to 80+ contributors including:

Ava Chow
MarcoFalke
Pieter Wuille
Ryan Ofsky
Gregory Sanders
And all Transifex translators

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