Alpenglow is the biggest upgrade in Solana’s history. It combines the latest advancements in consensus research with erasure-coded data distribution. The result is a protocol built for one job: finalizing blocks on a global network as fast as physics allows.
Votes Move Off Chain
More capacity for user transactions on the chain.
Resilience
Survives up to 40% of stake going offline.
Researched
Peer-reviewed, cutting edge research that works in the real world.
Internet capital markets
Markets that run 24/7 with the bandwidth to support global trading, where trades and contracts settle instantly.
Institutions
Transactions settle in ~150ms, not 1-3 business days, with a cryptographic guarantee. Payment processing moves onchain with no intermediary to reconcile against.
Solana with Alpenglow is ready for the token supercycle. Votes move out of band, creating more headroom for agents and micropayments. How does it do it? Votor.
Two voting tracks, one winner
Votor runs two voting modes concurrently. First mode finalizes a block in one round if 80% of stake responds. The second mode finalizes at 60% after two rounds. Which voting mode is fastest depends on where you are in the world. Alpenglow runs them side by side and lets them compete, so the first to finalize wins.
Skip logic
Proof of History is gone. Every node runs its own timers and independently identifies a silent leader. No more waiting on an unresponsive validator: nodes vote to skip, a skip certificate forms, the chain moves on. Liveness belongs to the validator network, not whoever holds the slot.
Votes leave the ledger
Alpenglow moves votes off chain and reclaims bandwidth. Votes become direct BLS-signed messages between nodes, and signatures aggregate into one compact certificate. Blockspace is now solely for users.
40% failure tolerance
20% adversarial plus 20% offline stake, tolerated simultaneously. TowerBFT handled under 33% adversarial stake. Alpenglow covers up to 40% of stake misbehaving or missing.
The Alpenglow migration runs the same way on each cluster, in this order:
Completed
Operators have rehearsed the migration numerous times over the last five months.
Completed
The first formal step on the activation path, the cluster where validators and operators stage their infrastructure.
Completed
The cluster app developers build against. Test your programs, your integrations, and your assumptions against deterministic finality before mainnet-beta migrates.
Upcoming
After our observation period confirms the earlier runs, migration will be announced.
Each cluster runs the full four-step migration sequence below. Nothing reaches mainnet-beta that hasn’t executed identically upstream, and each activation is its own milestone.
Activation
The Alpenglow migration feature gate (SIMD-0384) activates at an epoch boundary. Nothing migrates immediately.
The boundary
5,000 slots after activation, the migration boundary hits. Blocks stop carrying user transactions and hold only votes. This is what makes the handoff safe: every block past the boundary can be rolled back without losing anything a user signed.
Genesis
The migration boundary sits 5,000 slots after activation, so it never lands on an epoch boundary. At the migration boundary, validators wait for one block to get 82% of stake voting for it in the following slot. Typically, blocks receive 95%+, so the boundary block clears this immediately and TowerBFT produces just one more block before the handoff.
That block’s last ancestor before the boundary becomes the Alpenglow genesis block. Validators sign a BLS vote for it, and at 82% of stake, the genesis certificate forms.
The migration
Validators roll back everything after Alpenglow genesis, hand consensus to Votor, and re-allow user transactions. The certificate is packed into the first Alpenglow genesis block and written to an onchain account. This leaves a paper trail for validators to know when migration to Alpenglow consensus has occurred.
The handoff is expected to take hundreds of milliseconds. After that, TowerBFT is retired. Alpenglow runs from genesis block forward.
Rotor
The second half of the Alpenglow whitepaper. Rotor will replace Turbine's multi-layer tree with a single relay hop. Blocks are erasure-coded into slices, and every node relays a share proportional to its stake. Throughput stops being capped by the leader's upload bandwidth and draws on the network's total bandwidth instead, asymptotically optimal.
Fast leader handover
Reducing the transition time between leaders by optimistically starting block production before finalization.
Geo-aware leader handoff
Cut leader transition time by reducing the physical distance between leaders.
