Solana is preparing to activate its Transaction v1 format upgrade on September 9, 2026, increasing the maximum transaction size from 1,232 bytes to 4,096 bytes — roughly 3.3 times more space per transaction. The change stems from two proposals: SIMD-0296, which defines the size increase, and SIMD-0385, which defines the v1 format itself. Both were co-authored by Jacob Creech and Andrew Fitzgerald.
The larger envelope enables developers to include more instructions, signatures and account data in a single transaction. Use cases include zero-knowledge proofs, large multisignature setups and cross-chain operations. Previously complex operations had to be split across multiple transactions, creating risk if one step succeeded while another failed. Transaction v1 allows all instructions to succeed or fail together as one atomic operation.
Transaction v1 removes Address Lookup Tables used by v0, storing full 32-byte addresses directly in the transaction. The 64-account-per-transaction limit remains unchanged. Developers must explicitly set compute-unit and loaded-data limits in v1, since both default to zero. Infrastructure providers face the biggest compatibility risk: RPC providers, indexers, block explorers and analytics services must update their software or risk failing on v1 transactions or displaying incorrect data such as a zero priority fee when one was paid.
The upgrade is optional — legacy and v0 formats continue working under existing limits. Solana Foundation VP of Technology Jacob Creech confirmed September 9 as the target, although the official roadmap still labels mainnet activation as pending and Anza’s release schedule as tentative. Testnet and devnet have already activated the feature.
At the time of writing, SOL traded around $105.56, up roughly 0.8% over 24 hours. The weekly RSI has climbed to around 60. A CoinGlass liquidation heatmap shows dense leveraged positions between $145 and $150, with further clusters near $180-$200 and $240-$250, while downside liquidity sits around $60-$70. Solana derivatives open interest has risen back to roughly $6-$7 billion from the $4-$5 billion range, though still below the previous peak near $17 billion. Analyst SatoshiOwl suggested SOL could break toward $115-$116, but warned that extremely bullish sentiment at $116 could precede a sharp reversal.
