- Solana activated the Alpenglow consensus protocol on mainnet on October 21, 2026.
- The upgrade reduced block finality time from about 12.8 seconds to about 150 milliseconds.
- Alpenglow, built by Anza, fully replaces the TowerBFT consensus protocol.
Solana activated the Alpenglow consensus protocol upgrade on mainnet on October 21, 2026. The network described it as the biggest consensus upgrade in its history, cutting block finality time from about 12.8 seconds to about 150 milliseconds.
“Alpenglow is now live on Solana mainnet. Finality just went from ~12.8 seconds to ~150ms. The biggest consensus upgrade in Solana’s history, built by @anza_xyz,” Solana said in an October 21, 2026 post.
The upgrade fully replaces TowerBFT, the consensus protocol Solana had used since launch. The protocol allows validators to agree on transaction ordering and determine when a block is final and can no longer be reverted.
Anza announced on October 13 that Alpenglow would launch on October 21. The upgrade resulted from the team’s long-term work to change the blockchain’s core state agreement mechanism.
At the time, the developers described the project as “18 months of work to migrate […] in a single slot.”
Source: Incrypted
