Zcash has officially advanced its upcoming protocol overhaul, activating the NU7 network upgrade on its testnet and moving months of rigorous planning into a live testing environment just weeks ahead of a targeted mainnet rollout.
According to data from the Zcash testnet block explorer ZecBlock, block 4,465,026—which served as the scheduled activation point for the NU7 upgrade—was successfully mined on Oct. 4 at 18:21:45 UTC. Shortly after the milestone block was processed, the Zcash development team confirmed the successful deployment in a public post on the social media platform X, verifying that the NU7 upgrade is now fully operational on the testnet.
The successful testnet deployment marks a crucial operational phase for the privacy-focused cryptocurrency network. It gives core developers, node operators, and ecosystem participants several weeks to closely monitor, evaluate, and stress-test the protocol changes under real-world network conditions before a final decision is made regarding its integration onto the mainnet.
NU7 stands as Zcash’s next major network upgrade, bringing a comprehensive suite of protocol adjustments designed to enhance transaction efficiency, improve network security, and introduce structural economic changes. Among the most notable updates introduced in NU7 is a significant reduction in the network’s target block spacing. The upgrade aims to slash block times from the current 75 seconds down to a much faster 25 seconds, a modification intended to drastically improve transaction finality and overall user experience on the Zcash network.
In addition to accelerating block times, the NU7 upgrade implements several deep technical shifts. Most prominently, the protocol will completely disable version 4 transactions. This change carries critical implications for users holding funds within legacy infrastructure, specifically Zcash’s older Sprout shielded pool. Because version 4 transactions are being deprecated, any ZEC currently held within the Sprout shielded pool will become entirely unspendable unless users proactively move their funds to more modern, supported addresses prior to the full activation of NU7 on the mainnet.
Furthermore, the NU7 upgrade introduces a Network Sustainability Mechanism. This new feature is engineered to structurally redirect a designated portion of transaction fees into future block rewards, aligning the long-term economic incentives of network participants with the ongoing security and sustainability of the broader Zcash ecosystem.
Following the successful deployment on the testnet, the Zcash Foundation issued a statement urging testnet operators and developers to actively utilize the newly released candidate to test the NU7 protocol under realistic operating parameters. This live testing window is designed to provide the development community with empirical data regarding the stability, performance, and reliability of the 25-second block times and associated protocol modifications.
The insights gathered during this multi-week testnet phase will form the basis for the next major milestone in the upgrade timeline. Zcash developers are scheduled to convene on Oct. 20 to review the performance of NU7 on the testnet, assess any potential technical hurdles, and make a definitive final decision regarding mainnet activation, including the formal selection of the mainnet activation height.
Should the testnet phase proceed without encountering critical disruptions, the mainnet activation of the NU7 upgrade is tentatively targeted for November 5, representing one of the most substantial structural transitions for the Zcash network in recent years.
