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Solana Alpenglow goes live with 150ms finality target

Solana activated Alpenglow on Oct. 21, replacing TowerBFT with a system targeting 150ms finality that could speed payment settlement without changing wallets or fees.

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Solana Alpenglow goes live with 150ms finality target

Solana activated Alpenglow on mainnet on Oct. 21, replacing its old consensus system and targeting transaction finality in about 150 milliseconds, down from roughly 12.8 seconds, according to the Solana Foundation’s Alpenglow update.

That is a change to how quickly the network treats a transaction as settled. It does not change SOL itself, the way you send it, or the fees you pay.

What does 150ms finality mean for a SOL transaction?

Finality is the point when a transaction can no longer be reversed under the network’s rules. The 150ms figure is a target for that point, not a promise that every payment will appear in your wallet within 150 milliseconds.

That distinction matters if you use SOL or a Solana app to pay, trade or move funds. A service can act with stronger assurance sooner once a transaction is final. An exchange could credit a deposit sooner, for example, while a merchant could settle a payment with less waiting. CoinDesk says the target depends on network conditions and how quickly the service receives finality information.

How does Alpenglow cut the wait?

Alpenglow replaces TowerBFT, Solana’s consensus protocol. Validators—the computers that agree on the network’s records—used to record their votes as transactions and build approval over successive blocks.

Under Alpenglow, validators send votes directly to each other and combine approvals into certificates. The Solana Foundation says a block can then become final after one or two voting rounds. The change affects agreement on transactions, not their execution: the Foundation says Solana’s programs and transaction fees stay the same.

The upgrade went live in stages on Oct. 21. The Foundation says epoch 1064 began at about 13:36 UTC, with the network switching from TowerBFT to Alpenglow after a 5,000-slot transition window. The system took over at slot 459,653,000.

What should SOL users watch next?

You can keep using your existing wallet, and apps do not need to change how they run, according to CoinDesk’s report on what Alpenglow means for users. One visible difference may be lower transaction totals on network dashboards: validator votes no longer appear as on-chain transactions, so those totals may fall even if user payments and trades do not.

Alpenglow’s first phase, Votor, is live. The next phase, Rotor, is intended to change how block data moves across Solana, but the Foundation says it has not been scheduled. Watch for a Rotor release date and for services to show how quickly they act on finalized transactions.

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