The Solana blockchain has begun testing a significant upgrade, Alpenglow, on its testnet. Alpenglow aims to dramatically reduce transaction finality—the time it takes for a transaction to be considered irreversible—from the current 12.8 seconds to just 150 milliseconds.
According to a report from CoinDesk, Alpenglow has spent more than four months running on a smaller network created specifically for the upgrade. Moving it to Solana's established testnet checks whether the broader group of computers and services already running the blockchain can switch together.
Validators taking part in the test must use Agave 4.3, the main software used to run Solana, maintained by Anza, one of the companies responsible for developing the network. Anza recommended Agave 4.3 to all mainnet validators on September 21, after initially rolling it out to operators responsible for 10% and then 25% of the SOL used to secure the network.
September 28 appears in Anza's schedule as the tentative date for turning on features included in Agave 4.3 on the main network. However, it is not a confirmed Alpenglow launch date, and Anza's tracker still listed the testnet switch itself as pending early Wednesday.
Notably, Firedancer and Frankendancer—two alternative validator programs built by Jump Crypto—do not yet support the Alpenglow test. Those alternatives are intended to reduce Solana's reliance on a single piece of software, so a fault in Agave does not affect every validator at once. Their absence from the test means the first Alpenglow migration will run entirely through Agave.
According to Anza, applications will keep executing transactions as they do today, and users will not need to change wallets or how they send funds.