Solana plans to activate its Transaction v1 upgrade on Wednesday, raising the maximum transaction size from 1,232 bytes to 4,096 bytes and giving developers more than three times the current space for on-chain operations. The upgrade will allow large cryptographic proofs, multi-party approval payments and confidential transfers that previously required multiple transactions to be consolidated into a single transaction. The existing transaction format will remain supported, with no mandatory switch required for wallets or applications. Services that read Solana data must update to recognize the v1 format or requests may fail. Priority fee information has also been moved, meaning outdated software may display incorrect fees. The change is defined by SIMD-0296 and SIMD-0385, with the 4,096-byte limit based on the standard memory page size of validator hardware.