Solana moves to testnet a redesign aimed at making payments irreversible in under a second
Alpenglow swaps the network's slow-stacking vote chain for direct peer-to-peer confirmation. Validators need Agave 4.3 to join.
Illustration · generated, not a photograph
Solana has put Alpenglow, an upgrade designed to slash the time it takes a transaction to become irreversible, onto its public testnet. If it works as intended, that interval — known as finality — drops from roughly 12.8 seconds to about 150 milliseconds.
Finality is the point at which a payment can no longer be undone. Exchanges hold deposits until it arrives, cross-chain bridges release funds only after it, and merchants rely on it to confirm a sale won't be reversed.
Today Solana reaches that point through TowerBFT. In that scheme, validators post their votes onchain and accumulate them across 32 slots before a block is locked in. Alpenglow discards the accumulated-vote approach in favour of a new protocol called Votor, under which validators exchange votes directly with each other and can converge on a block in one or two rounds. The long trail of onchain votes disappears.
Everyday activity stays untouched. Applications continue executing transactions exactly as before, and wallet holders don't need to alter anything about how they send funds.
The move to the public testnet follows more than four months on a purpose-built, smaller network dedicated to the upgrade. Widening the trial tests whether the full spread of machines and services operating the chain can migrate in step.
Participation requires Agave 4.3, the primary client software for running Solana, developed by Anza. According to Anza's rollout, the firm first shipped 4.3 to operators covering 10% of staked SOL, then 25%, before recommending it to all mainnet validators on Sept. 21.
Not every client is on board. Firedancer and Frankendancer, alternative validator software from Jump Crypto built to reduce Solana's dependence on any single program, don't yet support the test. Because their purpose is to prevent a flaw in Agave from taking down all validators at once, the first Alpenglow migration will pass entirely through Agave.
Sept. 28 appears as the tentative activation date for Agave 4.3's feature set on mainnet, per Anza's schedule — but that is not a confirmed launch date for Alpenglow itself. As of early Wednesday, Anza's tracker still showed the testnet switch as pending.
Source reporting
The outlets whose reporting this account was written from.
Written from the reporting and primary documents credited at the foot of this story. Facts are credited to the outlet or document that established them. How Chainpress works
