Alpenglow is Live on Solana: The World's Fastest Finality on a Global Network

Solana's largest consensus upgrade since the network launched in 2020 brings sub-second, deterministic finality

SAN FRANCISCO, Oct. 21, 2026 /PRNewswire/ -- Anza, the leading core engineering team behind Solana, today announced that Alpenglow, Solana's new consensus protocol that brings finality down to sub-second speed, is live on Solana mainnet-beta. As Solana powers internet capital markets and increasingly becomes the infrastructure for financial applications, Alpenglow delivers the deterministic settlement speed that traditional finance requires. Transactions now become irreversible in about 150 milliseconds, down from 12.8 seconds.

At slot 459,653,000 on Wednesday October 21st at ~14:00 UTC, Solana's validators retired TowerBFT, the consensus protocol the network has run since its launch in March 2020. Migration was completed on the live Solana network.

The change is to finality, the point at which a transaction can no longer be reversed. It is what an exchange, a bank, or a merchant waits for before treating an asset as moved. For most of Solana's history, that finality took about 12.8 seconds whereas a conditional confirmation was provided within seconds. Alpenglow is designed to deliver the previous two step path condensed to one in roughly 150 milliseconds, about the length of a blink. Bringing finality assurance from seconds to a fraction of a second makes payment and trading applications even more responsive. For merchants accepting payments or exchanges crediting deposits, it means an even better user experience.

"This is the largest, most ambitious blockchain upgrade since 'The Merge' and Anza took it from a white paper to running on mainnet in under 18 months," said Brennan Watt, CEO, Anza. "This aggressive timeline was only possible because of the caliber of our development team and the incredible cast of ecosystem teams and validator operators that helped harden the protocol over the last several months."

The engineering achievement extends beyond speed. Validators replaced the consensus system at the heart of a running blockchain while carrying its existing ledger forward. Independent operators coordinated a shared handoff point from the previous protocol, TowerBFT, to Alpenglow, while maintaining availability.

Before reaching mainnet, Alpenglow underwent public testing – including red teaming and penetration testing, repeated migration rehearsals, and security competition. It was then launched on Solana's testnet and devnet. Anza developed the protocol and implemented it in Agave, the validator software it maintains; while independent validator operators adopted and activated the upgrade.

The Solana blockchain has no single operator. Anza is one of several independent teams that build software for the network. Its research team, led by ETH Zurich professor Roger Wattenhofer with Quentin Kniep and Kobi Sliwinski, published the Alpenglow design in May 2025.

Looking forward, there are additional Alpenglow related improvements to come. Rotor changes how block data spreads across the network. Geographically aware leader rotations help reduce the handoff latency between leaders. Quantumglow levels up Alpenglow for post-quantum security. It's a research design from Anza that swaps Alpenglow's elliptic-curve cryptography for hash-based signatures while keeping the same finality speed. These are planned for later releases and have no committed date yet. Status and technical details are at anza.xyz/alpenglow.

About Anza
Anza engineers Solana, shipping the software that pushes the boundaries of blockchain performance and scale. Founded by core Solana Labs engineers, Anza builds and maintains the software that validators run, researches the next generation of the protocol, and works with the ecosystem to roll out upgrades on a live network. Learn more at www.anza.xyz.

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SOURCE Anza Technology, Inc.