Solana activated its Alpenglow consensus upgrade on mainnet-beta on October 21, 2026, replacing TowerBFT at slot 459,653,000

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Solana validators approved the SIMD-0326 proposal implementing Alpenglow in September 2025 with over 98% voting in favor

Solana core engineering firm Anza developed the Alpenglow upgrade and took the protocol from a white paper to mainnet deployment in under 18 months

Alpenglow is designed to continue operating with up to 20% of stake acting maliciously and another 20% offline

Alpenglow condenses Solana's previous two-step transaction confirmation process under TowerBFT into a single step for finality

Moving validator votes off-chain under Alpenglow is expected to reduce Solana's reported transaction counts and TPS because vote transactions are no longer included in blocks

Under Alpenglow's Votor mechanism on Solana, validators send BLS-signed vote messages directly off-chain rather than submitting votes as block transactions

The Alpenglow upgrade reduces Solana's transaction finality from about 12.8 seconds to roughly 150 milliseconds

Anza plans a future upgrade named Rotor to replace Turbine and improve how block data spreads across the Solana network

During public testnet and devnet testing, Alpenglow achieved median finality times as low as 54 milliseconds

Alpenglow on Solana can finalize a block in one round if 80% of stake votes for it, or in two rounds requiring 60% of stake per round

Under Solana's Alpenglow upgrade, validators pay a flat 0.8 SOL per epoch fee rather than paying per-vote transaction fees

LayerZero is developing a proprietary blockchain network named Atlas

An amendment to XRP Ledger rules, such as fixCleanup3_4_0, requires continuous approval from over 80% of the network's 35 default trusted validators—at least 29 votes—for two consecutive weeks before activating

The XRP Ledger fixCleanup3_4_0 amendment reached 29 validator votes on October 9, 2026, and held 29 on October 19, 2026, tracking activation around 09:34 UTC on October 23, 2026, with a single validator withdrawal restarting its 14-day countdown.

The XRP Ledger evaluates amendment activation decisions at designated intervals called flag ledgers, occurring every 256 ledgers.

Under Solana's Alpenglow Votor system, Solana validators communicate directly off-chain to aggregate votes into cryptographic certificates rather than recording each vote as an onchain transaction

Transitioning to Solana's Alpenglow Votor system requires validator operators representing at least 82% of total staked SOL to sign a genesis certificate

The mainnet activation of Solana's Alpenglow v4.3.2 upgrade represents the largest consensus redesign and infrastructure overhaul in Solana's history

The Alpenglow upgrade targets a reduction in Solana's transaction finality time from approximately 12.8 seconds to roughly 150 milliseconds.

Solana research and development firm Anza announced that Solana's Alpenglow v4.3.2 upgrade is scheduled for mainnet-beta activation on October 21, 2026, at epoch 1064 around 14:50 UTC.