# Solana Alpenglow network upgrade > Live situation record from CLSTR: https://clstr.news/situations/solana-alpenglow-network-upgrade > Updated: 2026-10-21T08:50:20.000Z. Sources: 50. Developments: 7. Solana has successfully activated its Alpenglow network upgrade on the mainnet, marking its most significant technical overhaul since its 2020 launch. The transition occurred during epoch 1064, with the handover recorded on-chain at slot 459,653,000. The upgrade replaces the long-standing TowerBFT consensus mechanism with a new protocol called Votor, developed by Anza in collaboration with researchers from ETH Zurich. A primary objective of Alpenglow is to drastically reduce transaction finality times from approximately 12.8 seconds to a target range of 100–150 milliseconds. While early mainnet observations showed finality at roughly 202 milliseconds, the upgrade represents a massive increase in speed for decentralized finance (DeFi), high-frequency trading, and blockchain-based payment applications. To achieve this, the upgrade moves validator voting off-chain. Instead of recording every vote as an individual transaction on the blockchain, validators now exchange BLS-signed messages directly with one another, which are then aggregated into digital certificates recorded in block footers. This change is intended to optimize block capacity and is expected to cause a sharp drop in headline transaction counts and transactions per second (TPS) figures, though real network activity is not expected to decrease. The Solana Foundation has advised data services and analytics providers to reset their TPS baselines accordingly. Additionally, the upgrade is expected to reduce validator operating costs by approximately 60%, moving from a variable cost of roughly 2 SOL per day to a fixed fee of approximately 0.8 SOL per 24-hour period. To participate, validators must upgrade to the Agave 4.3.2 client. ## Claims - Solana activated the Alpenglow upgrade on its mainnet on October 21, 2026. (corroborated by 10 sources) - The upgrade targets a transaction finality of 150 milliseconds. (corroborated by 9 sources) - Validator voting is moved off-chain and aggregated into certificates. (corroborated by 9 sources) - Alpenglow replaces the TowerBFT consensus mechanism with the Votor protocol. (corroborated by 8 sources) - The price of Solana (SOL) has recently stabilized above the $120 level. (corroborated by 5 sources) - The upgrade is expected to reduce validator costs by approximately 60 percent. (corroborated by 4 sources) - The transition to Alpenglow occurred at slot 459,653,000. (corroborated by 4 sources) - The upgrade was preceded by six test network restarts and a failed migration attempt. (corroborated by 3 sources) - Validators must hold a minimum of 0.8 SOL in vote accounts as an admission fee. (corroborated by 3 sources) ## Timeline ### 2026-10-21: Solana activates Alpenglow consensus upgrade Solana has launched the Alpenglow upgrade, replacing TowerBFT with the Votor protocol to reduce transaction finality from 12.8 seconds to a target of 150 milliseconds. 17 sources. https://clstr.news/cluster/solana-implements-alpenglow-upgrade-to-accelerate-transactions ### 2026-10-19: Solana activates Alpenglow consensus upgrade on mainnet Solana has launched the Alpenglow upgrade, replacing TowerBFT with the Votor protocol to reduce transaction finality from 12.8 seconds to a target of 150 milliseconds. 8 sources. https://clstr.news/cluster/solana-prepares-for-alpenglow-upgrade-to-improve-transaction-finality ### 2026-10-16: Solana to launch Alpenglow upgrade to slash transaction finality Solana will activate the Alpenglow upgrade on October 21, replacing TowerBFT with Votor to reduce transaction finality from 12.8 seconds to 150 milliseconds. 7 sources. https://clstr.news/cluster/solana-to-implement-alpenglow-upgrade-to-reduce-transaction-finality ### 2026-10-14: Solana to launch Alpenglow upgrade on October 21 Solana will launch the Alpenglow upgrade on October 21, replacing TowerBFT with the Votor protocol to reduce transaction finality from 12.8 seconds to approximately 150 milliseconds. 7 sources. https://clstr.news/cluster/solana-to-launch-alpenglow-upgrade-on-october-21 ### 2026-09-28: Solana Alpenglow upgrade does not launch on September 28 Solana's Alpenglow consensus upgrade did not launch on its rumored September 28 date; the scheduled date instead marked the resumption of protocol feature gate activations. 2 sources. https://clstr.news/cluster/solana-alpenglow-upgrade-does-not-launch-on-september-28 ### 2026-09-25: Solana deploys Alpenglow upgrade to devnet to target 150ms finality Solana has deployed its Alpenglow upgrade to devnet, aiming to reduce transaction finality from 12.8 seconds to 150 milliseconds using the new Votor consensus system. 16 sources. https://clstr.news/cluster/solana-prepares-alpenglow-upgrade-to-reduce-transaction-finality-2 ### 2026-09-23: Solana prepares Alpenglow upgrade to reduce transaction finality Solana's upcoming Alpenglow upgrade aims to reduce transaction finality from 12.8 seconds to approximately 150 milliseconds, potentially making the process 85 times faster. 7 sources. https://clstr.news/cluster/solana-prepares-alpenglow-upgrade-to-reduce-transaction-finality-1 --- Cite as: Solana Alpenglow network upgrade. CLSTR, https://clstr.news/situations/solana-alpenglow-network-upgrade