Solana's Alpenglow upgrade has entered its public test network, where developers are working to slash transaction finality from approximately 13 seconds to 0.15 seconds — a 99% reduction that could transform how exchanges, bridges and merchants treat payments on the network.
Finality marks the moment a transaction becomes irreversible. Currently, Solana relies on its TowerBFT consensus system, in which validators record votes on-chain and must accumulate enough approvals across 32 slots before a block is considered final. Alpenglow replaces TowerBFT with a new voting protocol called Votor, which lets validators send votes directly to one another and reach finality in just one or two rounds of voting, eliminating the lengthy chain of on-chain vote stacking.
Applications will continue executing transactions as they do today, and users will not need to update wallets or change how they send funds, according to the project's description.
The initial testnet migration requires Agave 4.3, the primary validator software maintained by Anza. Firedancer and Frankendancer — two alternative validator programs built by Jump Crypto designed to diversify Solana's software dependencies — do not yet support Alpenglow. As a result, the first migration will run exclusively through Agave.
Before moving to Solana's main testnet, Alpenglow spent more than four months operating on a smaller, purpose-built network. The broader testnet rollout is intended to verify whether the larger network of computers and services can transition together.
Anza recommended Agave 4.3 to all mainnet validators on Sept. 21, having first rolled it out incrementally to operators securing 10% and then 25% of the SOL used to protect the network.
Sept. 28 appears on Anza's schedule as the tentative date for enabling Agave 4.3 features on mainnet, though it is not a confirmed Alpenglow launch date. As of early Wednesday, Anza's tracker still listed the testnet switch as pending.
