Alpenglow Goes Live on Testnet Solana's biggest consensus overhaul to date has reached its public testnet. According to @anza_xyz, the Alpenglow upgrade switched on @Solana's testnet on Thurs
Solana's biggest consensus overhaul to date has reached its public testnet. According to @anza_xyz, the Alpenglow upgrade switched on @Solana's testnet on Thursday around 17:30 UTC, with the new system taking over from TowerBFT roughly 17 minutes after the transition began.
The upgrade is designed to cut the time a transaction takes to become irreversible from about 13 seconds to just 0.15 seconds. Anza targets median finality of 100 to 150 milliseconds. Earlier simulations reached about 100 milliseconds under favorable conditions.
Solana currently uses TowerBFT, which carries a finality time of 12.8 seconds, the time it takes for a transaction to be irrevocably confirmed on the network.Under that system, validators record their votes onchain and accumulate enough confirmations across 32 slots before a block reaches finality.
Alpenglow replaces TowerBFT with Votor, which allows validators to finalize blocks after one or two rounds of direct voting, without changing how users send funds.The upgrade changes Solana's underlying consensus process without requiring application developers or ordinary users to adopt a different transaction system.
The initial testnet migration requires Agave 4.3 and will not support Firedancer or Frankendancer, while a Sept. 28 mainnet update remains tentative and is not a confirmed Alpenglow launch date. Devnet is next in the rollout sequence, with no scheduled mainnet date confirmed.
Alpenglow has already spent more than four months operating on a smaller community cluster created specifically to test the consensus system, meaning Thursday's testnet activation marks the first time the upgrade runs on infrastructure that more closely mirrors the live network at scale.
Anza first moved Alpenglow into community validator testing in May, describing the project at the time as the largest consensus change in Solana's history.
Sources:CoinDesk: Solana starts testing upgrade that could cut finality from 12.8 seconds to 150 millisecondsCrypto.news: Solana Alpenglow testnet explainedCoinCodex: Solana could go from 12.8 seconds to 150ms finality as Alpenglow enters testing
