Solana has scheduled its Alpenglow network upgrade for October 21, 2026 , targeting a cut in transaction finality from about 12.8 seconds to roughly 150 milliseconds. The change aims to make a payment irreversible almost as quickly as it first appears confirmed, replacing the voting system validators use to agree on blocks.
Key takeaways
Alpenglow’s activation is tied to Solana’s epoch 1064.
Votor will move validator voting off-chain.
Validators face new software requirements and a 0.8 SOL admission fee.
Users will keep the same transaction formats and fees.
According to Decrypt , the Solana Foundation expects epoch 1064 to begin around 15:00 UTC that Wednesday. CoinDesk also reported the schedule, stressing that 150 milliseconds is a performance target rather than a fixed outcome under all network conditions.
Solana network upgrade set for October 21
Alpenglow ’s activation will begin at the start of epoch 1064, following validator approval in September 2025. The governance proposal, SIMD-0326 , received support from 98.27% of votes cast.
The feature gate switches on in one slot, but the handover is staged. For an additional 5,000 slots, about 18 minutes , TowerBFT will keep managing consensus until Alpenglow assumes control at slot 459,653,000. The report describes that interval as a measure to support stability during the transition.
Votor replaces TowerBFT to shorten finality
With Alpenglow, TowerBFT is swapped out for Votor , a protocol under which validators communicate directly with one another instead of recording votes on-chain. Validators combine those votes into certificates, allowing a block to become final after one or two voting rounds.
Finality is the point at which a transaction becomes irreversible. TowerBFT currently takes about 12.8 seconds to reach that point, accumulating votes across 32 slots. Alpenglow targets roughly 150 milliseconds , narrowing the gap between an initial confirmation and a final settlement.
The voting thresholds determine how quickly that happens. A block finalizes in the first round when at least 80% of stake supports it. With support between 60% and 80%, a second round using 60% thresholds determines whether the block is finalized or skipped.
Moving votes off-chain also changes how network activity appears in transaction statistics. CoinDesk reported that headline transaction counts could fall sharply once validator votes disappear from blocks, even if user trading and payment activity stay unchanged.
Validators need new software and an admission fee
Validators must prepare both their software and vote-account balances for the Solana network upgrade. CoinDesk reported that operators need software based on Agave 4.3.0 ; Firedancer and Frankendancer will not support the initial migration, requiring their operators to switch temporarily.
Each vote account must hold an additional 0.8 SOL beyond its rent-exempt balance to cover the Validator Admission Ticket. This per-epoch fee is burned and replaces the roughly 1 SOL per epoch validators previously spent on vote transactions under TowerBFT.
Users keep existing formats, while Rotor comes later
Ordinary users do not need to take action for Alpenglow, and wallets and applications should continue behaving as before. Transaction formats, programs, user fees and the Solana Virtual Machine remain unchanged.
For developers, the “confirmed” and “finalized” commitment levels become the same. The faster finality target addresses the waiting period between a payment appearing successful and becoming irreversible—a distinction relevant to merchants, decentralized finance applications and settlement.
The October 21 rollout introduces Votor, the first part of Alpenglow. A later component, Rotor, is intended to replace Turbine, the system Solana uses to distribute block data among validators.
Article produced with the assistance of artificial intelligence and reviewed by the editorial team.
