- Anza plans to activate Solana’s Alpenglow consensus protocol on the main network on October 21, 2026.
- The upgrade is expected to reduce block finality from about 12.8 seconds to approximately 150 milliseconds.
- Alpenglow will replace TowerBFT in the biggest change to Solana’s consensus mechanism since the network launched.
Anza, which develops client software for Solana, will activate the Alpenglow consensus protocol on the main network on October 21, 2026, at about 14:50 UTC, or 17:50 in Kyiv. The upgrade is expected to cut block finality from about 12.8 seconds to approximately 150 milliseconds, making transaction confirmations nearly instantaneous.
The change will be the biggest upgrade to Solana’s consensus mechanism since the network launched. According to the Solana Foundation, activation will occur during epoch 1064.
“18 months of work for a migration that happens in one slot,” Anza said in its October 13 announcement. The team also published additional details about the launch.
How Alpenglow will change Solana
Alpenglow will completely replace TowerBFT, the consensus protocol Solana has used since its launch. Consensus allows validators to agree on the order of transactions and determine when a block can no longer be reversed.
Under the current system, validators submit votes as transactions, and a block reaches finality after enough votes accumulate over 32 slots. With Alpenglow, validators will exchange votes directly and bundle them into certificates, allowing a block to finalize in one or two voting rounds.
Moving validator voting off-chain is expected to free additional space for user transactions and increase throughput. The protocol is also designed to continue operating if as much as 40% of the network’s stake becomes unavailable.
The upgrade will not change the Solana virtual machine, transactions, programs or fees, maintaining backward compatibility for existing applications and users.
Testing and development
Anza unveiled Alpenglow in May 2025. Solana co-founder Anatoly Yakovenko called it the best thing to happen to the network and emphasized the importance of maximizing throughput efficiency and achieving single-round finality.
In May 2026, Anza reported the first deployment of the new consensus mechanism on a community test cluster. At the time, the developers expected to launch Alpenglow on the main network in the following quarter.
The upgrade has also attracted attention from market participants. In September 2025, MEXC Research chief analyst Shawn Yang linked SOL’s potential rise to $215 that month and $250 by year-end to staking, institutional demand and Alpenglow’s prospects.
Source: Incrypted
