Add as a preferred source on GoogleSolana Schedules Alpenglow Mainnet Upgrade for Oct. 21, 2026
The consensus change targets finality in about 150 milliseconds, compared with roughly 12.8 seconds under TowerBFT. Epoch timing may shift the estimated activation time.
Solana is scheduled to begin activating Alpenglow on its mainnet Oct. 21, 2026, in a change to validator consensus designed to cut transaction finality from about 12.8 seconds to a target of roughly 150 milliseconds.
The activation is expected to start with epoch 1064 at about 11 a.m. ET (15:00 UTC). The time is an estimate because epoch timing can shift. TowerBFT is scheduled to continue for 5,000 slots, or about 18 minutes, after the feature gate turns on, with Alpenglow expected to take over at slot 459,653,000.
Alpenglow’s Votor protocol sends validator votes directly between validators instead of recording them in on-chain transactions. Its design provides a faster finalization path when validators holding 80% of stake certify a block, and a slower path that uses two certificates with 60% thresholds.
The upgrade changes how validators agree on blocks. Transaction execution, programs and fees remain the same. Because vote transactions will no longer appear in blocks, transaction counts may change even if user activity does not.
The first phase covers voting and finality. A later phase, Rotor, is planned to replace Turbine, Solana’s block-data distribution system, but has no scheduled release date.
Validator operators need an Agave-based client built on Agave 4.3.0. They also need at least 0.8 Solana (SOL) above the vote account’s rent-exempt minimum to cover the Validator Admission Ticket fee. The 150-millisecond figure is a target; mainnet performance after activation has not yet been established.
More details on validator preparations for the migration are available in TokenPost’s earlier coverage.
Simon Yoon
ReporterSimon Yoon reports on blockchain technology for TokenPost. Send corrections or tips to info@tokenpost.com.