Zcash NU7 Testnet Launches Early With 25-Second Blocks
Zcash has launched its NU7 upgrade on the public testnet ahead of schedule, significantly reducing the target block time from 75 seconds to 25 seconds. This move comes ahead of the planned November mainnet rollout and aims to improve transaction efficiency. The upgrade went live at block 4,465,026, allowing exchanges, wallets, and infrastructure providers to test the new rules in a live environment. At the time of the launch, Zcash was trading near $1,341.
The NU7 upgrade introduces a threefold reduction in block spacing without altering the long-term issuance schedule of ZEC. To maintain the emission trajectory, the block rewards have been reduced to one third. Additionally, the upgrade changes the distribution of transaction fees, with 40% going to miners and 60% being reserved for future mining rewards. This adjustment ensures that the faster block production does not accelerate the issuance of new coins.
The upgrade also phases out version 4 transactions used by Sprout, Zcash’s oldest privacy system. Users with funds in the Sprout pool are advised to move them before the mainnet activation to avoid losing access. The public testnet launch provides operators with an opportunity to measure the impact of faster confirmations before the mainnet upgrade.
Both major node implementations, Zakura and Zebra, now support the public test. Developers plan to review the test results on October 20 before deciding on the mainnet activation, currently targeted for November 5. The early testnet launch accelerates real-world validation but does not finalize the mainnet upgrade, leaving performance review and activation-height selection as remaining steps.