Updated: Solana Activates Transaction v1 With a 4,096-Byte Limit
Solana activated Transaction v1 on the mainnet on September 15. The new format increases the maximum size of a single transaction to 4,096 bytes but requires infrastructure support.
Solana Transaction v1 has been active on the mainnet since September 15, 2026. The txv1 feature gate was enabled at the start of epoch 1035 at approximately 01:00 UTC. The new format increases the maximum size of a single transaction from 1,232 to 4,096 bytes.
This is an increase of approximately 3.3 times. However, the additional space is available only for Transaction v1. The older legacy and v0 formats remain functional, so existing applications do not have to switch to the new format automatically.
Solana Transaction v1 Provides More Space in a Single Operation
The activation changes the previous plan into a feature available on the production network. Developers who choose to use Transaction v1 can transfer more data in a single atomic transaction.
Sending v1 transactions is not mandatory. However, applications using this format must explicitly set selected resource limits. With v1, the configuration is read from transactionConfig, not from ComputeBudget instructions.
Transaction v1 also does not support address lookup tables. When selecting a format, developers must therefore take this incompatibility into account.
RPC Services, Indexers and Explorers Need an Update
The change affects more than just applications that create transactions. RPC clients, indexers, explorers and other services processing blocks must support version 1 and its different method of reading limits. Without an update, processing errors or misinterpretation of data from v1 transactions could occur.
With the new format, services must read resource limits from transactionConfig instead of ComputeBudget instructions. Infrastructure operators must therefore adapt parsers and clients to the new format.
Backward compatibility with the legacy and v0 formats also means that networks and applications can continue operating as before. The higher 4,096-byte limit does not apply to such older transactions.
Operational Data Will Show Its Real-World Use
The activation itself does not confirm what impact the new limit will have on costs, latency, the use of ZK proofs or the share of larger transactions. These figures cannot yet be reliably confirmed from operational data after activation. Likewise, it is not appropriate to compare the change directly with other blockchains based only on the maximum size of a serialized transaction, since networks use different formats, limits and execution models.
Announcements from RPC providers, wallets and explorers about Transaction v1 support will be another signal. It will also be important to see whether incidents occur in unupdated indexers or clients when processing blocks.
Sources
- Solana Foundation — Larger Transaction Sizes – Confirms activation of the
txv1feature gate on the mainnet on September 15, 2026, at approximately 01:00 UTC, the 4,096-byte limit and infrastructure compatibility requirements. - Solana Explorer — txv1 feature gate – This is the official explorer record for the Transaction v1 feature gate on the mainnet.
- SIMD-0385 — Transaction V1 Format – Defines the v1 format, the 4,096-byte limit, resource-limit configuration and the absence of address lookup tables.
- SIMD-0296 — Larger Transaction Size – Documents the increase from 1,232 to 4,096 bytes, possible uses and the technical risks of larger transactions.
Verified and updated: 09/15/2026 15:29
