Solana Alpenglow upgrade enters public testnet: transaction finality target shortened to 150 milliseconds

The Alpenglow upgrade of the blockchain network Solana has entered the public testnet, where developers will test reducing transaction finality from about 13 seconds to 0.15 seconds, or 150 milliseconds. This upgrade will replace Solana's existing TowerBFT consensus system with Votor, allowing validators to confirm blocks through one to two rounds of direct voting, but the way users send funds will not change.

The first testnet migration requires using Agave 4.3 and does not currently support Firedancer or Frankendancer. The mainnet update on September 28 is still a tentative arrangement and not a confirmed launch date for Alpenglow.