As Alpenglow goes live on Solana’s mainnet, developer team Anza announced that transaction finality has fallen from about 12.8 seconds to 150 milliseconds.
According to a statement Anza shared with The Block, the transition took place on Wednesday, October 21, at approximately 17.00 Turkey time, at slot number 459.653.000. This replaced TowerBFT, the consensus protocol the network had used since its launch in March 2020.
Earlier in the day, we covered the planned Alpenglow transition and its speed target. The new announcement confirms that the expected change is now active on the mainnet.
Less waiting for exchange deposits and payments
The new protocol changes how validators reach agreement on transactions, reducing the previous two-step confirmation process to a single step. The finality time of about 150 milliseconds cited by Anza is roughly one-seventh of a second.
In practice, this means faster finality for exchanges waiting on the network before crediting deposited assets, and for businesses before treating a payment as complete. Applications will still have their own review and processing times.
Unlike the roughly six-second starting time cited in the previous report, Anza’s new announcement makes the comparison using a 12.8-second finality time. Both announcements give 150 milliseconds as the time for the new system.
From the 2025 design to the mainnet transition
Anza published the Alpenglow design in May 2025. Before the mainnet transition, it conducted public testing, security work against attack scenarios, penetration testing, repeated transition rehearsals, and a security competition.
Anza CEO Brennan Watt described the work as the biggest and most ambitious upgrade in the blockchain space since Ethereum’s The Merge transition. This assessment reflects the development team’s view of the upgrade’s scope.
What comes next?
The team is also working on Rotor, which will change how block data is transmitted across the network, and location-aware task scheduling designed to reduce delays between block producers. Quantumglow, a separate research design, aims to use different signature methods for post-quantum security while maintaining fast finality.
No firm release date has been announced for these upcoming efforts.
Not investment advice.