Solana activates Transaction V1 upgrade to increase transaction size

Solana implemented the Transaction V1 upgrade on September 15, 2026, increasing the maximum transaction size from 1,232 bytes to 4,096 bytes. The update, activated at the start of mainnet epoch 1,035, allows for more complex atomic transactions, such as those involving zero-knowledge proofs or large multisignature wallets. The change does not impact network throughput, fees, or confirmation speeds, but requires developers and service providers to update their systems to support the new format.