Solana has launched its Alpenglow consensus upgrade, marking the network's most significant technical transition since its 2020 inception. The update replaces the long-standing TowerBFT protocol, reducing transaction finality time from approximately 12.8 seconds to roughly 150 milliseconds.
The transition occurred at slot 459,653,000 on Wednesday at 14:00 UTC. Validators migrated the existing ledger to the new system, which consolidates confirmation and finality into a single step. The design, published in May 2025 by the Anza research team, allows validators to exchange weighted votes directly.
The protocol maintains functionality even if 20% of the stake is malicious and another 20% is offline. If block finalization stalls for 10 seconds, the system automatically adjusts block times to ensure network continuity. The upgrade was approved by 98% of validators in September 2025.
Looking forward, the development team has outlined additional projects, including Rotor for data distribution and Quantumglow for quantum-resistant cryptography. Furthermore, the activation of Alpenglow enables potential future changes, such as removing the current 60 million compute unit cap per block.
