Zcash NU7 Testnet Cuts Block Time to 25 Seconds

Zcash has activated its NU7 network upgrade on the public testnet, reducing the targeted time between transaction blocks from 75 seconds to 25 seconds as developers prepare for a potential November mainnet launch.

NU7 went live at block 4,465,026, with Zcash tracking software Zakura confirming that the new network rules are active. The project's earlier standalone testing network has now been discontinued.

The shorter Zcash block time is designed to improve transaction speed for users, merchants and cryptocurrency exchanges. Since each block contains a batch of transactions, generating blocks more frequently could allow payments and deposits to receive confirmations faster.

For example, a service requiring three confirmations would face a targeted wait of roughly 75 seconds under NU7, compared with about 225 seconds previously, assuming its confirmation policy remains unchanged. Actual confirmation times can vary.

The public testnet uses tokens with no monetary value, allowing developers, node operators and infrastructure providers to evaluate NU7 before the changes reach the Zcash mainnet. Both major node implementations support the trial. Zakura released its compatible software on Oct. 1, followed by a test version of the Zcash Foundation's Zebra software on Oct. 2.

NU7 also changes how Zcash transaction fees are distributed. Miners will receive 40% of fees, while the remaining 60% will be removed from circulation and recorded in a reserve intended to support future mining rewards as newly issued ZEC declines.

Despite blocks being produced three times faster, ZEC issuance will not triple. Rewards per block will fall to one-third of their previous level, preserving the cryptocurrency's existing issuance schedule.

The upgrade also disables transactions using Sprout, Zcash's oldest private-payment system. Users holding funds there will need to move them before mainnet activation to retain spending access through the existing system.

Developers plan to review testnet results and decide on mainnet activation on Oct. 20. Nov. 5 remains the target launch date, although a final activation block has not yet been announced.