Solana's Alpenglow upgrade runs on devnet and testnet with 100-150ms finality target
Anza activated Alpenglow on Solana's testnet on Sept. 24 and devnet on Sept. 25, retiring TowerBFT on both networks and targeting finality of 100-150 milliseconds instead of about 12.8 seconds.
Why it matters
Alpenglow has not touched the network that holds real funds, and the finality figures are targets rather than measured mainnet results, so nothing changes for users or validators today. The upgrade matters for how quickly exchanges, payment apps and market makers can treat Solana transactions as irreversible once it ships, and the outstanding Votor work in competing validator clients would determine when that can happen.
Where the sources disagree
Alpenglow finality target
roughly 150 milliseconds
CoinDesk, Crypto.News, Bitcoin Insider
100 to 150 milliseconds
Bitcoin.com News, Crypto News (CryptoNews.net)
CoinDesk, Crypto.News and Bitcoin Insider give roughly 150 milliseconds, while Bitcoin.com News and its syndicated copy give a 100-150 millisecond range.
Name of the system that replaces TowerBFT
direct votes replacing onchain validator vote transactions
Crypto.News
Votor replaces TowerBFT
Bitcoin.com News, Crypto News (CryptoNews.net)
Crypto.News describes Alpenglow as replacing onchain validator vote transactions with direct votes, while Bitcoin.com News and its syndicated copy name the replacement as Votor.
Key facts
Anza activated Alpenglow on Solana's public testnet on Sept. 24 and on devnet on Sept. 25, retiring TowerBFT on both networks.
Reported by CoinDesk
The upgrade targets transaction finality of about 150 milliseconds compared with roughly 12.8 seconds under the current system.
150 msDisputed figureReported by CoinDesk
Bitcoin.com News reports Alpenglow targets finality of 100 to 150 milliseconds and replaces TowerBFT with a system called Votor.
Disputed figureReported by Bitcoin.com News
The testnet transition ran a 5,000-slot countdown of about 17 minutes and completed at slot 444,625,255, where the last TowerBFT block carried 82% of stake.
82 %Reported by Crypto News (CryptoNews.net)
Devnet completed its transition at slot 504,148,999.
504,148,999Reported by Crypto News (CryptoNews.net)
Alpenglow removes validator vote transactions from blocks, which lowers reported transaction counts even if user activity does not change.
Reported by CoinDesk
Anza has not scheduled a mainnet activation and mainnet still runs TowerBFT, with the finality target unproven under live conditions.
Reported by CoinDesk
The Alpenglow spec SIMD-0326 received governance approval in September 2025 with 98.27% of participating votes.
98.27 %Reported by Crypto News (CryptoNews.net)
What happened
Anza, the company building Solana's core validator software, activated the Alpenglow consensus upgrade on public testnet on Sept. 24 and on devnet on Sept. 25, retiring the existing TowerBFT system on both clusters. Bitcoin.com News reports the testnet transition followed a 5,000-slot countdown of about 17 minutes and finished at slot 444,625,255, with the final TowerBFT block carrying 82% of stake and an Alpenglow genesis block taking over finalization; devnet completed its switch at slot 504,148,999. The upgrade replaces onchain validator vote transactions with direct votes that can finalize a block in one or two rounds, which CoinDesk and Crypto.News say will cut reported transaction totals even if user activity is unchanged. Outlets differ on the target: CoinDesk, Crypto.News and Bitcoin Insider describe roughly 150 milliseconds of finality against the current 12.8 seconds, while Bitcoin.com News reports a 100-150 millisecond range. Anza has set no mainnet date, mainnet still runs TowerBFT, and CoinDesk and Bitcoin.com News both say the speed target has not been demonstrated under live-market conditions. CoinDesk also reports that Firedancer and Frankendancer still need to add Votor support, and Crypto News says the underlying spec, SIMD-0326, won governance approval in September 2025 with 98.27% of participating votes after a community cluster rehearsed the change from May, including an attempt that needed a restart.
How the story developed
- Official statement
Alpenglow activated on public testnet after a 5,000-slot countdown
Transition completed at slot 444,625,255; the final TowerBFT block carried 82% of stake.
- Official statement
Alpenglow activated on devnet, completing the switch on both public networks
Devnet transition completed at slot 504,148,999; the Solana Foundation upgrade page lists Alpenglow as active on devnet and testnet.
- Official statement
Co-founder Anatoly Yakovenko says the network is unprepared for the upgrade
Yakovenko marked the devnet countdown with the remark 'You are not ready for this.'
- First report
First report by CoinDesk
Solana’s 150-millisecond settlement upgrade reaches second public test network
- Independent corroboration
Independently corroborated by Crypto.News
Solana’s Alpenglow upgrade reaches devnet with 150ms finality target
- Official statement
Official statement from Bitcoin.com News
Solana’s Alpenglow Hits Second Testnet, 100ms Finality in Sight
- Update
Firedancer and Frankendancer still need to add Votor support before the transition is complete
- Official statement
Alpenglow approved by Solana governance as SIMD-0326 with 98.27% of participating votes
- Update
Community cluster begins rehearsing the consensus change, including a failed attempt requiring a restart
How coverage built up
Independent sources over time, counted the way the consensus panel counts them: a republication of a wire story does not move the line.
- 26 Sept 2026, 05:00 UTC: CoinDesk — 1 independent source, 1 reports
- 26 Sept 2026, 08:07 UTC: Crypto.News — 2 independent sources, 2 reports
- 26 Sept 2026, 16:04 UTC: Bitcoin Insider — 3 independent sources, 4 reports
- 26 Sept 2026, 21:45 UTC: Bitcoin.com News, official — 4 independent sources, 5 reports
Affected entities
Original sources
| Publisher | Report | Role | Published |
|---|---|---|---|
| Bitcoin.com News Company, official | Solana’s Alpenglow Hits Second Testnet, 100ms Finality in Sight | Independent | |
| CoinDesk Crypto media | Solana’s 150-millisecond settlement upgrade reaches second public test network | Original | |
| Crypto.News Crypto media | Solana’s Alpenglow upgrade reaches devnet with 150ms finality target | Independent | |
| Bitcoin Insider Aggregator | Solana Alpenglow Reaches Its Second Public Testnet | Syndicated | |
| Crypto News (CryptoNews.net) Aggregator | Solana's Alpenglow Hits Second Testnet, 100ms Finality in Sight | Syndicated | |
| Bitcoin Insider Aggregator | Solana’s Alpenglow Upgrade, Targeting 150ms Finality, Reaches Second Testnet | Aggregated |
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