Zcash Moves to 25-Second Blocks on Public Testnet Ahead of Plan

Zcash has switched on its NU7 upgrade on the public testnet, reducing the target time between blocks from 75 seconds to 25 seconds. The trial allows exchanges, wallets and developers to test the faster transaction cycle ahead of the planned November mainnet rollout.

The upgrade took effect at block 4,465,026. Zakura, a software implementation that tracks Zcash activity and validates transactions, now shows the new consensus rules running on the public testnet. The earlier, separate testing network has been shut down.

Since each block contains a batch of transactions, producing blocks at shorter intervals could reduce processing times for merchants and exchanges. If a service continues to require three confirmations, its target waiting period would decline from 225 seconds to roughly 75 seconds. Actual block intervals may differ from the 25-second target.

The public testnet uses coins with no monetary value, giving developers and infrastructure providers a risk-free environment to evaluate the changes before they affect real ZEC.

Both major Zcash node implementations now support NU7 testing. Zakura released its implementation on Oct. 1, followed by the Zcash Foundation’s test version of Zebra on Oct. 2. Operators must run compatible versions to participate in the upgraded network.

NU7 Changes Fee Allocation and ZEC Rewards

NU7 also changes how Zcash transaction fees are distributed. Miners will receive 40%, while the remaining 60% will be removed from circulation and assigned to a reserve designed to support future mining rewards.

The move to 25-second blocks will not cause ZEC issuance to increase threefold. Instead, the reward for each block will be reduced to one-third, preserving the network’s planned issuance schedule.

The upgrade also disables Sprout transactions, which are part of Zcash’s oldest private-payment system. Users with Sprout funds will need to move them before mainnet activation if they want to continue spending those funds through the existing system.

Developers plan to review the public testnet results on Oct. 20 and decide whether NU7 is ready for mainnet. Nov. 5 remains the target date, although a specific activation block for mainnet has not yet been set.