Zcash Activates NU7 Network Upgrade on Testnet Ahead of Targeted November Mainnet Release

Privacy-focused cryptocurrency Zcash has officially taken a major step toward its next protocol evolution by activating the NU7 network upgrade on its testnet. This development successfully transitions the anticipated protocol modifications into a live testing environment approximately one month ahead of its targeted mainnet rollout.

According to data from the Zcash testnet block explorer ZecBlock, block 4,465,026—which marked the scheduled activation point for NU7—was successfully mined on Oct. 4 at 18:21:45 UTC. The project’s developers and official channels quickly confirmed the milestone, taking to social media platform X to announce that the NU7 upgrade was officially live on the testnet. This deployment initiates a critical trial period that allows core developers, node operators, and the broader community to observe how the newly coded rules perform under realistic network conditions.

The NU7 upgrade represents a comprehensive set of improvements designed to fundamentally alter several operational parameters of the Zcash network. Among the most prominent changes introduced in NU7 is a significant structural shift in block generation times. The upgrade seeks to dramatically reduce the network’s target block spacing from the historical 75 seconds down to a much faster 25 seconds. By accelerating block times, developers aim to improve transaction confirmation speeds and enhance the overall user experience across the decentralized ecosystem, bringing Zcash closer to the responsiveness expected by modern digital asset users.

Beyond modifying block times, NU7 implements vital cryptographic housekeeping and economic model adjustments. The upgrade officially disables version 4 transactions, a legacy transaction format that has been phased out in favor of newer, more secure cryptographic structures. However, this specific change carries a critical consequence for long-term holders: any ZEC currently held within Zcash’s legacy Sprout shielded pool will become entirely unspendable unless users actively migrate those funds prior to the full activation of NU7 on the mainnet. The urgency of this migration has been a focal point of recent community communications, as failure to act before the cutoff will leave legacy funds permanently locked in the deprecated pool.

Additionally, NU7 integrates a newly formulated Network Sustainability Mechanism. This protocol-level feature is designed to redirect a designated portion of transaction fees back into future block rewards, creating a more sustainable economic feedback loop that supports the network’s long-term security and operational longevity.

Following the successful testnet deployment, the Zcash Foundation issued an advisory statement urging testnet operators and community validators to utilize the newly released software candidate to evaluate NU7 under real operational conditions. This preliminary phase serves as a vital safeguard, providing developers with the empirical data necessary to assess system stability, identify potential bugs or unforeseen friction points, and ensure that the codebase is robust enough for production-grade deployment.

The insights gathered during this testnet trial period will directly inform the final governance and operational timeline. Zcash developers are officially scheduled to convene on Oct. 20 to review the testnet performance data, make a definitive final decision regarding mainnet activation, and formally lock in the precise activation block height. Assuming the testnet phase proceeds without critical complications, the overarching deployment schedule points toward a mainnet activation on Nov. 5, marking a major milestone in the ongoing evolution of the privacy-centric blockchain network.