Solana is not switching on Alpenglow at some secret date: the release schedule maintained by the development shop Anza names September 28, 2026 for feature activation on mainnet. If you hold Solana (SOL), in most cases you need to do nothing at all. If you stake by delegating yourself, you have exactly one job, and the date that matters more for it is not September 28 but September 21.
This article answers the question of when Solana's Alpenglow activation happens, at the primary source, in three steps: what the schedule actually says, what "activation" means technically, and how far the network stands on the day of this measurement from the state the schedule assumes. The figures on how far the new version has spread were collected by us on mainnet on September 1, 2026.
When Solana Alpenglow will be activated: the Agave 4.3 schedule names September 28
The answer sits in a document almost nobody reads: the release schedule for Agave v4.3 in the validator client's wiki. Agave is the software ...


English (US)