Solana’s Alpenglow upgrade cuts finality to about 150ms

Solana activated Alpenglow on Oct. 21, replacing the voting system it has used since its 2020 launch and targeting transaction finality in about 150 milliseconds. That could let apps treat payments and exchange deposits as settled sooner. The Solana Foundation’s Alpenglow update says the change is live on mainnet.

What changes when a Solana transaction is final?

Finality is the point when a transaction can no longer be reversed. Under Solana’s previous system, TowerBFT, that took about 12.8 seconds. The Foundation says Alpenglow targets roughly 150 milliseconds.

The change affects how validators—computers that check transactions and agree on the network’s records—reach agreement. Previously, validators recorded their votes as transactions and approvals built up across blocks. With Alpenglow, validators send votes directly to each other and combine them into certificates. A block can then become final after one or two rounds of voting.

CoinDesk reported that the handover took about 900 milliseconds. It said votes from 446 of 654 participating validators certified the block that started the new system.

How could users notice the faster settlement?

Many apps already showed transactions as confirmed before they were fully final. Alpenglow shortens the remaining wait, which could help services that need stronger assurance before releasing money or goods.

For example, an exchange could credit a deposit sooner so a customer can trade, or a shop could confirm a stablecoin payment while the customer is still there. The 150-millisecond figure is a target, not a guaranteed time for every transaction. How soon a user sees finality also depends on the service handling the payment, CoinDesk reported.

Wallets and apps keep working as before, and the Foundation says transaction fees and execution are unchanged. Users do not need to take action.

Why might network dashboards show fewer transactions?

Alpenglow votes no longer appear as transactions in blocks. That means dashboards that counted validator votes may show lower transaction totals after the upgrade, even if users keep making payments and trades.

That change matters when comparing activity before and after activation: the old totals included validator votes alongside user transactions. The Foundation says the upgrade changes how blocks are agreed on, while the way transactions execute stays the same.

Sources

• Solana Foundation’s Alpenglow update — solana.com