Solana’s Alpenglow upgrade set to cut finality to 150ms

Solana is scheduled to swap out its consensus engine today. The Alpenglow upgrade is set to activate at approximately 13:20 UTC, with a target of shrinking finality from 12.8 seconds to 150 milliseconds. The activation is pegged to epoch 1064 on October 21, 2026. If it goes as planned, the network retires TowerBFT, the voting system it has relied on for a long time, and moves to a new protocol called Votor. What Alpenglow actually changes Under TowerBFT, deterministic finality on Solana took about 12.8 seconds. Alpenglow aims to bring that down to roughly 150 milliseconds. The engine behind that jump is Votor. Instead of validators recording their votes as transactions inside blocks, Votor collects direct votes from validators off-chain. It then bundles them using BLS signatures, a cryptographic method that compresses many signatures into one compact proof. Block production time is also expected to tighten to around 200 milliseconds after the upgrade. Notably, the change sits at the consensus layer only. The existing transaction execution layer and user interfaces are meant to stay the same, so wallets and apps shouldn’t need to relearn how Solana works. Testing gave the upgrade a ...