Solana sets Sept. 9 date for Transaction V1 upgrade

Solana Foundation Vice President Jacob Creech announced that the Transaction V1 upgrade is scheduled for September 9, 2026, raising the maximum transaction size from 1,232 to 4,096 bytes. Additionally, a five-stage rent reduction targeting a 90% cost savings begins the week of August 31, 2026. Solana has also reduced target slot times to 350 milliseconds, with plans for further reductions, while targeting October 2026 for the Alpenglow consensus redesign to achieve 150-millisecond finality.

Transaction V1 upgrade

• ▪Solana Foundation Vice President of Technology Jacob Creech announced on August 30, 2026, that the Solana Transaction V1 upgrade is scheduled to activate on September 9, 2026.
• ▪The Solana SIMD-0296 proposal indicates the larger Transaction V1 format can support zero-knowledge proofs, complex multisignature instructions, BLS signatures, and cross-chain operations.
• ▪Solana developers must manually opt into the Transaction V1 format, allowing existing legacy and version-zero transactions to remain compatible and valid on the network.
• ▪The Solana Transaction V1 upgrade will increase the network's maximum serialized transaction size from 1,232 bytes to 4,096 bytes, representing an approximate 3.3-fold increase.
• ▪The Solana Transaction V1 format will not support address lookup tables, requiring applications to decide which format suits each transaction.

Solana rent reduction rollout

• ▪The first stage of a five-step Solana network rent reduction is scheduled to begin during the week starting August 31, 2026.
• ▪The five-stage Solana rent reduction plans to eventually lower the rent calculation by 90 percent, from 6,960 lamports per byte to 696 lamports per byte.
• ▪The code for the Solana rent reduction was included in Agave 4.2, but validators must activate the changes separately via independent feature gates.

Slot time reduction roadmap

• ▪Solana has reduced its target slot time from 400 milliseconds to 350 milliseconds, with subsequent planned stages targeting 300, 250, and 200 milliseconds.
• ▪The Solana Transaction V1 upgrade scheduled for September 9, 2026, will not automatically reduce slot times, which require separate validator feature activations.

Alpenglow consensus redesign

• ▪Solana developers target October 2026 for the Alpenglow consensus redesign alongside the expected Agave 4.3 release, though this is not a guaranteed mainnet activation date.
• ▪Alpenglow is Solana's proposed consensus redesign that aims to reduce transaction finality to approximately 150 milliseconds compared to the current consensus system.

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