Solana prepares Alpenglow upgrade to reduce transaction finality

Solana is preparing for a major network upgrade known as Alpenglow, which aims to significantly reduce transaction finality times. The upgrade targets a reduction from approximately 12.8 seconds to roughly 150 milliseconds, making the finalization process about 85 times faster.

Finality refers to the point at which validators reach enough agreement for a block to be considered irreversible. While the upgrade will not change transaction costs, wallets, or the total number of transactions the network can process, it will cause the “confirmed” and “finalized” stages of a transaction to converge much more rapidly.

According to developer Anza’s rollout tracker, the Alpenglow feature (identified as SIMD-0326) is currently listed under “Pending Testnet Activation.” The upgrade is associated with the Agave v4.3.0 release. While a tentative date of September 28 has been mentioned in some planning, an official activation epoch for the public testnet has not yet been published. Currently, alternative validator clients such as Firedancer and Frankendancer do not support the feature.