Solana’s Alpenglow consensus upgrade has launched on its second public testnet, targeting a reduction in final confirmation time to 150 milliseconds.

Solana’s planned Alpenglow upgrade has been rolled out on devnet and testnet in succession, providing application teams with a testing environment ahead of the mainnet switch. The upgrade aims to cut transaction finalization time from the current ~12.8 seconds to around 150 milliseconds, drastically reducing the wait time for transactions to release deposits or for payment apps to notify merchants of completed trades. Solana development firm Anza announced on September 25 that the devnet had completed its switch; the testnet transition was finalized the day before, and the Solana Foundation’s upgrade page shows Alpenglow is active on both networks. Alpenglow changes how validators reach consensus on network records: validators will exchange votes directly instead of recording votes as transactions within blocks, condensing consensus into just one or two voting rounds. Removing these votes will also lower some Solana activity chart metrics: the total number of transactions including validator votes will decrease, even if actual payments and trading volumes remain unchanged.